DeLL E152FPc Goes black after a second.
Samantha
about a second after it is powered on. The Green power light stays on
and the color bar test pattern is there if you stick a flash light up to
it.
I have never had one of these apart and am not really sure what I am in
for. Just looking at it, I don't see any obvious way to take it apart.
There are some screws to take off the stand, but after that I am not
sure.
Anybody ever take one of these apart and fix it?
Would greatly appreciate any help.
Thanks so much!!!
S.
D Yuniskis
> I have a Dell E152FPc Flat screen Monitor 15" that goes black after
> about a second after it is powered on. The Green power light stays on
> and the color bar test pattern is there if you stick a flash light up to
> it.
>
> I have never had one of these apart and am not really sure what I am in
> for. Just looking at it, I don't see any obvious way to take it apart.
>
> There are some screws to take off the stand, but after that I am not
> sure.
>
> Anybody ever take one of these apart and fix it?
Most likely bad capacitors in the inverter (or the bulk
supply feeding it). There are a HUGE number of Dell variants
so you might be able to find a similar monitor with a different
set of "trailing letters" in the model number (I've never
bothered to sort out the presumed meaning of all these
variations)
Most of these cases snap together. A very small slotted
screwdriver and/or one of the "blanks" used to fill an
empty "card slot" in a PC is invaluable.
Find a seam between the front and rear halves of the
display's case. *Think* about how the two pieces
are probably fitted together (i.e., one fits inside/behind
the other). Then, slide your tool into the seam and
*gently* pry them apart.
You can usually slide the tool along the seam until you
can "feel" where the catches are located. Usually, there
is symmetry -- the catches on the left side are placed in the
same locations as those along the right edge; ditto for
top and bottom (within reason). Also, there tends to be symmetry
about the vertical and horizontal axes -- so, if there is a catch
1" down (from the top) the left side, there is probably one 1"
*up* (from the bottom) on that side.
Experiment along the bottom -- someplace where your mistakes
aren't as cosmetically visible. (remember, plastic deforms easily
so you can easily gouge it with your tool).
Good luck!
Samantha
D Yuniskis <not.goi...@seen.com> wrote:
Thanks, am fighting a really bad summer cold right now and am not really
up to messing with it.. But in the next day or so I will probably feel
well enough to take a crack at it...
Appreciated everyones input!
Jeff Liebermann
wrote:
>I have a Dell E152FPc Flat screen Monitor 15" that goes black after
>about a second after it is powered on. The Green power light stays on
>and the color bar test pattern is there if you stick a flash light up to
>it.
The LCD backlighting inverter has died. Everything else is probably
just fine. The really tiny inverters are tricky to repair as a
shorted turn on the xformer will usually blow up all the switching
FET's. However, this one is big and easy to work on. I still suggest
replacement. Tear apart the monitor and get the part number off the
LCD inverter. Then search eBay and Google for a scrap replacement.
One of these looks right:
<http://www.lcdrepair.us/e152-e153fpc-inverter-power.html> $40.
<http://www.lcdrepair.us/e152-e153fpc-inverter-power-2.html> $30
>I have never had one of these apart and am not really sure what I am in
>for. Just looking at it, I don't see any obvious way to take it apart.
>
>There are some screws to take off the stand, but after that I am not
>sure.
>
>Anybody ever take one of these apart and fix it?
Bulging and leaking electrolytic caps are the most common problem.
Look at the board and you'll see about 8 electrolytic capacitors. If
they're even slighly bulging, they're bad. I'm lazy and replace them
all rather than trying to figure out which ones are blown. However,
with LCD inverters, the switching FET's are also commonly fried. If
replacing the caps doesn't work, I suggest just buying a replacement
board..
>Would greatly appreciate any help.
Ummm.... you've heard of Google perhaps?
<http://video.google.com/videosearch?hl=en&source=hp&q=lcd+monitor+repair#>
<http://www.lcd-monitor-repair.com>
Lots more when searching for "LCD monitor repair".
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com je...@cruzio.com
# http://www.LearnByDestroying.com AE6KS
Jeff Liebermann
wrote:
>Weakest link = inverters. Verify voltage source first, forget what
>they usually run but a guess would be around 20 vdc?
Now I know why we used to kill off a tech a year in the 2-way biz in
Smog Angeles during the 60's and 70's. They didn't know low from high
voltage. Duz the big fat insulation on the output leads offer a clue?
Try about 500-700VDC output.
<http://www.fonerbooks.com/test.htm>
The frequency range is also a problem. These bests run around
30-70Khz which is often beyond the upper frequency range of the
typical DVG (Digital-Volts-Guesser). I'm not sure if the high
frequency or the high voltage did the damage but I've killed at least
2 cheapo (Harbor Freight) DVM's measuring LCD inverter output. I've
also managed to get electrocuted several times, mostly due to haste,
sloppiness, clip leads, or all the aformentioned.
Plain...@yahoo.com
wrote:
Most of the monitor repair sites are nothiing more than an attempt to
sell an overpriced book 'How to repair LCD monitors'.
This specific problem is often referred to as the 'two seconds to
black' failure. A quick explanation of the operation of most
inverters, and the failure: The inverter has a controller IC that
generates the signals that drive the transformers AND monitors the
voltage and current outputs of the inverter. Usually the start up
sequence consists of driving the CCFL backlights at full brightness
for several seconds, then beginning to monitor the output voltage
across and current through each CCFL. If the output voltage is too
high or too low, or if the current is too high, for any CCFL the
controller will shut down.
Possible causes of this problem include bad CCFLs, a shorted
transformer, breakdown of insulation in the wiring, or bad components
in the monitoring circuits. The Dell E152FPc and related models use
an unusual design in the inverter driver; a bad transistor can also
cause this problem. And yes, bad capacitors could also be
responsible.
This monitor also combines the inverter with the power supply. This
makes replacement difficult unless you can obtain a non-working
identical monitor inexpensively. Buying through eBay is usually
impractical. The cost of shipping is prohibitive.
Rather than spending the time and money to repair a 15" monitor in the
USA I usually suggest watching the local Craigslist and Freecycle
sites for somone giving away 'dead' LCD monitors. Currently I am
using a 23" wide screen monitor I purchased for $15, and repaired by
replacing ALL electrolytic caps at a cost of $7. My lates acquisition
was a 19" Dell which had a broken power button. Not only was it a
simple repair, the donor DELIVERED it!!!
One site I STRONGLY recommend is www.badcaps.net/forum. They have
extensive discussions on repairing many LCD monitors, including this
one. Registration is required to post, but is free.
PlainBill
Jim Yanik
news:si8qc5ddk4a4sl60b...@4ax.com:
> On Wed, 07 Oct 2009 08:27:36 -0400, Meat Plow <me...@petitmorte.net>
> wrote:
>
>>Weakest link = inverters. Verify voltage source first, forget what
>>they usually run but a guess would be around 20 vdc?
>
> Now I know why we used to kill off a tech a year in the 2-way biz in
> Smog Angeles during the 60's and 70's. They didn't know low from high
> voltage. Duz the big fat insulation on the output leads offer a clue?
>
> Try about 500-700VDC output.
I think he was talking about INPUT DC being ~20VDC
><http://www.fonerbooks.com/test.htm>
> The frequency range is also a problem. These bests run around
> 30-70Khz which is often beyond the upper frequency range of the
> typical DVG (Digital-Volts-Guesser). I'm not sure if the high
> frequency or the high voltage did the damage but I've killed at least
> 2 cheapo (Harbor Freight) DVM's measuring LCD inverter output.
Because they are only 1 Meg input Z.
I took one apart to check it,was debating redoing the divider to 10MegR
total.Also,the AC section will not handle freqs over 1 Khz.
> I've
> also managed to get electrocuted several times, mostly due to haste,
> sloppiness, clip leads, or all the aformentioned.
Not "electrocuted",but shocked.
"electrocution" is to KILL with electricity. Since you're still posting,you
aren't killed. ;-)
>
BTW,you can make a nifty HV probe for a 10Meg DMM by using a string of
22.5Meg 1% metal film R's to make 90 MegR,and putting it inside a plastic
tube like an old tuning tool,solder to a 6-32 screw and threaded 1/4" hex
spacer,a wire lead with banana plug on the other end,and use an old TEK 500
series probe hook-tip,or other TEK accessory tips.
Makes a nice 10:1 probe,and 100 MegR doesn't load the HV supplies so much.
I've used mine for a couple of decades.
--
Jim Yanik
jyanik
at
localnet
dot com
Matthew Fries
wrote:
>I have a Dell E152FPc Flat screen Monitor 15" that goes black after
I had one of these that did the same thing yours is doing. I replaced
a couple of transistors in the power supply. Here is a link to the
disassembly gude (with lots of pictures) to help you get it open:
http://www.lcdrepair.us/files/e172fpbinstall.pdf
I used an old credit card to open the sides. A metal screwdriver will
chew up the plastic and deform it too much.
Thanks.
Remove the BALONEY from my email address.
-----------------------------------------------------
Matthew Fries Minneapolis, MN USA
fre...@baloneyvisi.com
"Quit eating all my *STUFF*!" - The Tick
Jake
I recently repaired 3 E153FP's, which I believe are virtually
identical.
The problem was a 1000uF, 16 volt capacitor, used for the power
supply. It had excessively high ESR, and I am assuming it caused
excessively high ripple voltage which was making the LCD's control
circuitry wack out (that's my very technical description of what I
thought was going on, ha ha). I replaced the same cap on all 3 - It
was easy to identify, about the largest cap on the board, the PCB
material was darkened around it, and the top of the cap was bulged.
Good luck! The 3 I fixed had the exact same symptom you describe, and
have been back in service for about 3 months with no further problems.
-Jake
Jeff Liebermann
Some random comments.
>Most of the monitor repair sites are nothiing more than an attempt to
>sell an overpriced book 'How to repair LCD monitors'.
True. However, the OP appears to be a beginner and an overpriced book
might be a good start. Some others just sell parts:
<http://www.ccl-la.com/monitor_repair.htm>
I question whether it's worth the time and effort to repair a 15" LCD
monitor, but this sounds like a personal repair job, not a business.
It takes me about an hour to tear apart a monitor, replace all the
cazapitors, reassemble, and test. At $75/hr, that exceeds the value
of all 15" monitors making commercial repair uneconomical even if the
parts were free. Anything that keeps it out of the eWaste pile is
probably justifiable.
>The Dell E152FPc and related models use
>an unusual design in the inverter driver
Not that unusual. This one has two boards, power supply + LCD supply,
and a logic board. I think the PS is made by BenQ, but I'm not sure.
>Buying through eBay is usually
>impractical. The cost of shipping is prohibitive.
Does $20 plus $6 shipping seem prohibitive for do it thyself?
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360193406812>
I buy quite a few parts and pieces on eBay. Most are fair prices. A
few times, I get cheated.
>Rather than spending the time and money to repair a 15" monitor in the
>USA I usually suggest watching the local Craigslist and Freecycle
>sites for somone giving away 'dead' LCD monitors. Currently I am
>using a 23" wide screen monitor I purchased for $15, and repaired by
>replacing ALL electrolytic caps at a cost of $7. My lates acquisition
>was a 19" Dell which had a broken power button. Not only was it a
>simple repair, the donor DELIVERED it!!!
Nice. I have about 10 such monitors hidden in the closet waiting for
me to find the time to raise them from the dead. Most are
backlighting or power supply issues. Most were customer "upgrades"
where they wanted a newer bigger monitor. I use them as loaners when
working.
>One site I STRONGLY recommend is www.badcaps.net/forum.
Nice. Thanks for the analysis and the links.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
D Yuniskis
> On Wed, 07 Oct 2009 17:28:42 -0700, Plain...@yahoo.com wrote:
>
>> Most of the monitor repair sites are nothiing more than an attempt to
>> sell an overpriced book 'How to repair LCD monitors'.
>
> True. However, the OP appears to be a beginner and an overpriced book
> might be a good start. Some others just sell parts:
> <http://www.ccl-la.com/monitor_repair.htm>
> I question whether it's worth the time and effort to repair a 15" LCD
Agreed. I stopped repairing 15's quite a while ago. Then 17's.
Now I am getting ready to give up on the 19's (except for wide
screen format monitors). They tie up a lot of work space and
prices have fallen such that you can buy (economy) versions of
even the larger sizes for less than what it costs in time and
materials to fix (and not have to deal with the possibility of
discovering the screen is "smudged" after you've made the repair)
> monitor, but this sounds like a personal repair job, not a business.
> It takes me about an hour to tear apart a monitor, replace all the
> cazapitors, reassemble, and test. At $75/hr, that exceeds the value
> of all 15" monitors making commercial repair uneconomical even if the
> parts were free. Anything that keeps it out of the eWaste pile is
> probably justifiable.
There are lots of businesses/individuals that will harvest bad
monitors for parts (display panels, lamps, etc.) so you should
be able to find a non-landfill outlet for your unwanted units.
Heck, there are folks still salvaging CRTs!
>> Buying through eBay is usually
>> impractical. The cost of shipping is prohibitive.
>
> Does $20 plus $6 shipping seem prohibitive for do it thyself?
> <http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360193406812>
> I buy quite a few parts and pieces on eBay. Most are fair prices. A
> few times, I get cheated.
Just make sure that you don't end up with a "pull"... :>
D Yuniskis
> On Oct 6, 6:19 pm, Samantha <saman...@comcast.net> wrote:
>> I have a Dell E152FPc Flat screen Monitor 15" that goes black after
>> about a second after it is powered on. The Green power light stays on
>> and the color bar test pattern is there if you stick a flash light up to
>> it.
>>
>> I have never had one of these apart and am not really sure what I am in
>> for. Just looking at it, I don't see any obvious way to take it apart.
>>
>> There are some screws to take off the stand, but after that I am not
>> sure.
>>
>> Anybody ever take one of these apart and fix it?
>>
>> Would greatly appreciate any help.
>>
>> Thanks so much!!!
>
> identical.
Dell has subtle variations in these monitors -- none that I
have been able to *quickly* identify (at least not enough
that I could open one and determine which model it was just
by examining its contents!)
> The problem was a 1000uF, 16 volt capacitor, used for the power
> supply. It had excessively high ESR, and I am assuming it caused
> excessively high ripple voltage which was making the LCD's control
> circuitry wack out (that's my very technical description of what I
> thought was going on, ha ha). I replaced the same cap on all 3 - It
> was easy to identify, about the largest cap on the board, the PCB
> material was darkened around it, and the top of the cap was bulged.
The PCB darkening is usually from the nearby switching transistor.
When replacing the cap(s), select high temperature devices (105C)
from "reputable" manufacturers (I like panasonic). You want a low
ESR cap on most of these applications -- something "designed for
switching applications" (I like the FM series as a reasonable
cost/performance point). Note that you can also purchase
different *grades* of "low ESR caps". So, if you are repairing
a particularly "cherry" monitor for your *own* use, you might
opt for something rated at ~10,000 hours (instead of ~5,000).
Also, pay careful attention to the *height* of the component!
I've been bitten by components that were just a bit too tall
to fit back into the case (*with* the metalic shield installed).
Lead spacing is also a concern but usually something you can
work around.
> Good luck! The 3 I fixed had the exact same symptom you describe, and
> have been back in service for about 3 months with no further problems.
It probably wouldn't hurt to examine the other caps on the board
for "likely future failures". Certain manufacturers tend to
have lots of early failures (I joke that "Xom" in the name
means "gonna crap out soon"). Since most of the "cost" of
the repair is getting the unit apart and then back together,
the extra time and expense to replace all likely candidates
seems justifiable.
Jeff Liebermann
<not.goi...@seen.com> wrote:
>Now I am getting ready to give up on the 19's (except for wide
>screen format monitors).
Not exactly. I'm finding a substantial demand for 4:3 aspect ratio
LCD monitors. Anyone dealing with vertical page oriented text finds
that the height really matters. A 16:9 LCD is fine for watching
DVD's, but a real challenge when doing desktop publishing or document
preparation. In the past, LCD's would rotate to a vertical position,
but that seems to be a feature missing in most 16:9 monitors. I've
had numerous calls for people looking for 4:3 monitors. I can usually
find a few new 4:3 monitors on NewEgg and TigerDirect, but those will
eventually dry up. So, I save the good ones (19" or bigger) and just
wait for the phone calls.
>They tie up a lot of work space and
>prices have fallen such that you can buy (economy) versions of
>even the larger sizes for less than what it costs in time and
>materials to fix (and not have to deal with the possibility of
>discovering the screen is "smudged" after you've made the repair)
Yep. However, I don't let them hog the bench space. I have some
conveniently sized cardboard boxes that fit LCD's vertically. I also
have some anti-static foam bags for protecting the screen.
Good point about screen defects discovered after the repair. That
hasn't happened too often. What I see is water damage near the bottom
of the LCD caused by compulsive screen cleaners. Also, it is easy
enough to apply voltage to the CCFL backlight bulbs after you tear it
apart to see if there are any cracks or damage.
>There are lots of businesses/individuals that will harvest bad
>monitors for parts (display panels, lamps, etc.) so you should
>be able to find a non-landfill outlet for your unwanted units.
>Heck, there are folks still salvaging CRTs!
Yep. They want to buy the scrap by the ton. Very few will buy
untested scrap electronics because there's no way to know if it will
work when resold. I do some trading with such vendors, but I always
have to guarantee (100% refund) everything we sell each other.
>>> Buying through eBay is usually
>>> impractical. The cost of shipping is prohibitive.
>>
>> Does $20 plus $6 shipping seem prohibitive for do it thyself?
>> <http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360193406812>
>> I buy quite a few parts and pieces on eBay. Most are fair prices. A
>> few times, I get cheated.
>
>Just make sure that you don't end up with a "pull"... :>
That's the problem. For example, I just bought a DC controller for an
HP LaserJet 4200. Big crack on the formatter PCB. I could send it
back as defective and get another, or just patch the board and be done
with it. I'll probably phone the eBay vendor and see what he has to
offer. That's one of the risks of buying obviously used parts.
Where I get into bigger problems is buying replacement board for
products that have a manufacturing related problem. If one board is
sick or dead, it's highly likely all the boards will be in the same
condition. I had to deal with a motherboard that was just too much
work to replace all the bad caps. However, it was obvious that all
the replacement boards selling on eBay had exactly the same problem
because all the vendors listed their boards as no-return.
Caveat emptor.
D Yuniskis
> On Thu, 08 Oct 2009 08:50:36 -0700, D Yuniskis
>
>> screen format monitors).
>
> Not exactly. I'm finding a substantial demand for 4:3 aspect ratio
> LCD monitors. Anyone dealing with vertical page oriented text finds
> that the height really matters. A 16:9 LCD is fine for watching
> DVD's, but a real challenge when doing desktop publishing or document
Understood. My point is that the price/repair point is quickly
moving to make 19" as uneconomical to fix as the 17's have become.
> preparation. In the past, LCD's would rotate to a vertical position,
> but that seems to be a feature missing in most 16:9 monitors. I've
I have a Dell that rotates. But, in order to do so, the display
has to be "up" high enough (so the rotating end doesn't wack
into the tabletop). This places the display too high for me
in my normal usage.
[N.B. I have been told by folks who wear bifocals that even
*my* display height is too high for them to use comfortably;
they end up having to tip their heads too far back to bring
the screen into the correct portion of the eyeglass lens to
focus]
I do a lot of DTP and have found that I can get pretty good
performance out of nearly any "large-ish" display. When
working on prose, etc. I zoom the image to "fit width".
This gives me lots of detail (when you've got 1600 dots
to play with :> ) and enough of the page vertically that I
can see what I am doing. I only look at full page views
when I want to get a feel for the layout of the page,
the location of whitespace, etc.
A second monitor is invaluable in just about any desktop
(not just DTP) application. It lets you work in one *full*
screen while having another (full!) screen for other uses
(e.g., floating pallets for image editing, "text" that
you are copy/pasting into the actual application, a OCB
schematic alongside the PCB *layout* you are working on,
etc.)
> had numerous calls for people looking for 4:3 monitors. I can usually
> find a few new 4:3 monitors on NewEgg and TigerDirect, but those will
> eventually dry up. So, I save the good ones (19" or bigger) and just
> wait for the phone calls.
>
>> They tie up a lot of work space and
>> prices have fallen such that you can buy (economy) versions of
>> even the larger sizes for less than what it costs in time and
>> materials to fix (and not have to deal with the possibility of
>> discovering the screen is "smudged" after you've made the repair)
>
> Yep. However, I don't let them hog the bench space. I have some
> conveniently sized cardboard boxes that fit LCD's vertically. I also
> have some anti-static foam bags for protecting the screen.
Most of the displays I've fixed have too many "things" hanging
off of them (cabling to speakers or pushbuttons attached to the
front bezel, etc.). Plus, the *stands* don't store well
(bulky). Living room floor works well -- but only for a limited
number of displays! :> (there are currently six 21 inch LCDs
awaiting pats in various states of disassembly... this causes
a fair amount of grief! And, isn't realistic when you have
pets :< )
> Good point about screen defects discovered after the repair. That
If I did this for a *living*, I would just keep a spare inverter
around and hack it into the "bad" display long enough to illuminate
the display (using a nice "white" test screen) to check for these
"smudges" before investing much time in the repair.
> hasn't happened too often. What I see is water damage near the bottom
> of the LCD caused by compulsive screen cleaners. Also, it is easy
Ah! I've not seen that! I should start looking more closely.
> enough to apply voltage to the CCFL backlight bulbs after you tear it
> apart to see if there are any cracks or damage.
>
>> There are lots of businesses/individuals that will harvest bad
>> monitors for parts (display panels, lamps, etc.) so you should
>> be able to find a non-landfill outlet for your unwanted units.
>> Heck, there are folks still salvaging CRTs!
>
> Yep. They want to buy the scrap by the ton. Very few will buy
> untested scrap electronics because there's no way to know if it will
> work when resold. I do some trading with such vendors, but I always
> have to guarantee (100% refund) everything we sell each other.
We've found folks who will gladly take the (known to be defective)
LCD monitors that I won't bother to repair. I think maybe $10
or so per display (which is pretty good considering "general
eWaste -- from which the plastic and metal cases haven't been
removed -- sells for much less than $1/pound)
>>>> Buying through eBay is usually
>>>> impractical. The cost of shipping is prohibitive.
>>> Does $20 plus $6 shipping seem prohibitive for do it thyself?
>>> <http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360193406812>
>>> I buy quite a few parts and pieces on eBay. Most are fair prices. A
>>> few times, I get cheated.
>> Just make sure that you don't end up with a "pull"... :>
>
> That's the problem. For example, I just bought a DC controller for an
> HP LaserJet 4200. Big crack on the formatter PCB. I could send it
> back as defective and get another, or just patch the board and be done
> with it. I'll probably phone the eBay vendor and see what he has to
> offer. That's one of the risks of buying obviously used parts.
Exactly. And, if the cost of return postage becomes an issue,
it might not be economical to even *try* to return it (most
ebay sellers don't consider the threat of a "negative" to be
important; especially if they are selling in volume)
> Where I get into bigger problems is buying replacement board for
> products that have a manufacturing related problem. If one board is
> sick or dead, it's highly likely all the boards will be in the same
Yup. This is a double-edged sword; it can also be a *boon* as you
fix *one* and you know how to fix them *all*. I ran through a
few dozen ViewSonic LCD monitors in a matter of a few days just
by making the same repairs on each of them.
What I find more frustrating is when a manufacturer changes
design within a particular model. I recently had an "identical"
pair of 17" HP LCDs. Since 17" is below my threshold for repair,
I only quickly looked at them: one had a bad inverter, the other
had a bad *display*! OK, this is a real simple fix -- just
cannabilize the two to build *one*.
After tearing (literally) the first one apart to salvage the
inverter (hey, the rest of the display is scrap so why bother
being careful with the disassembly?? :> ), I *carefully*
disassembled the second unit (the one with the good screen)
to remove and replace *its* inverter.
Only to discover that the inverter's design had been changed
mechanically. Not only had the connectors to the CCFL's
been "rendered incompatible", but the board mounting wasn't
compatible, either!
<frown> Would have been better (from a standpoint of my time)
had they *both* been defective! ;-)
> condition. I had to deal with a motherboard that was just too much
> work to replace all the bad caps. However, it was obvious that all
On motherboards, replacing caps is considerably more risky as
the boards are often 4 (or even 6) layers and often don't
have thermal reliefs around the caps. Unless it is a particularly
nice board, I don't bother (you also have no way of knowing if
the high ripple on those power signals hasn't toasted something
else in the design.
I'm just now re-cap-ing the power distribution boards (allows
redundant power supplies to coexist) in some Dell servers.
But, the boards in question are relatively low-tech so I don't
fear damaging them -- or the other components on them. And,
the caps sit on the outputs of the power supplies so they
are somewhat "redundant".
> the replacement boards selling on eBay had exactly the same problem
> because all the vendors listed their boards as no-return.
<grin> Yeah, its always amusing to see how they act as if they
don't *know* anything about the board(s). As if "untested"
meant "Gee, I haven't had time to check them" whereas what
they really mean is "I didn't BOTHER to test them cuz I'm
pretty damn *sure* they're crap!" :-/
> Caveat emptor.
Plain...@yahoo.com
As a rule of thumb, when a monitor has a defective cap, I will replace
the lot of them. As you point out, it's not worth the risk of having
to open the monitor up again.
I prefer Panasonic FM or FC series for replacements. Purchasing from
Digikey, I can redo an entire monitor for under $10, including
shipping. (OK, I seldom replace the 100 �F 450 Volt cap).
PlainBill
D Yuniskis
> As a rule of thumb, when a monitor has a defective cap, I will replace
> the lot of them. As you point out, it's not worth the risk of having
> to open the monitor up again.
>
> I prefer Panasonic FM or FC series for replacements. Purchasing from
> Digikey, I can redo an entire monitor for under $10, including
> shipping. (OK, I seldom replace the 100 �F 450 Volt cap).
I've only seen one of these "bad" (in about 100 monitors).
Despite the fact that they are often manufacture by the same
company who manufactures the other (crappy) caps on the
board! I guess the ripple currents are not as large (?)
Samantha
Didn't find much online when I went and searched for it. This is the
first time I have had had one of these apart and didn't really know what
to expect. It belongs to my aunt and I said I would take a quick look
at it.
The bad cap list was a good tip, really appreciate that, as well as the
PDF on how to disassemble the monitor.
Tomorrow is a pretty full day for me so I hope to be feeling up to
pulling this apart by saturday.
Thanks again.
S.
Jeff Liebermann
<not.goi...@seen.com> wrote:
>Understood. My point is that the price/repair point is quickly
>moving to make 19" as uneconomical to fix as the 17's have become.
Yep. I just did a quick search using Google Shopping for "19" LCD
monitor". Quite a few refurbished units for $70 to $100. New for
about $120 to $150. Not very economical to repair at $75/hr.
>I have a Dell that rotates. But, in order to do so, the display
>has to be "up" high enough (so the rotating end doesn't wack
>into the tabletop). This places the display too high for me
>in my normal usage.
Not mine. However, I made my own out of a swivel plate with detents
as inspired by:
<http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/>
The lazy susan is a bit too crude for me. However, all my office and
home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide
screen monitors might seem a bit high, but I've built two of these for
customers and they loved it. One is a script writer and the other a
technical editor, which might explain their interest in portrait mode
displays.
>[N.B. I have been told by folks who wear bifocals that even
>*my* display height is too high for them to use comfortably;
>they end up having to tip their heads too far back to bring
>the screen into the correct portion of the eyeglass lens to
>focus]
I'm 61 years ancient, wear bifocals, and don't have a problem. That's
because I don't use the bifocals in front of the screen. I'm
fortunate and can still use the cheap "reading" glasses without
correction for computer use. For driving, I need bifocals.
Plug: Cheap prescription glasses:
<http://www.zennioptical.com>
>I do a lot of DTP and have found that I can get pretty good
>performance out of nearly any "large-ish" display. When
>working on prose, etc. I zoom the image to "fit width".
>This gives me lots of detail (when you've got 1600 dots
>to play with :> ) and enough of the page vertically that I
>can see what I am doing. I only look at full page views
>when I want to get a feel for the layout of the page,
>the location of whitespace, etc.
Well, I've been told that I have no writing ability, no aesthetic
sense, no appreciation of layout styles, and no artistic abilities.
That's a sufficient to avoid DTP and other forms of real work. About
the only layout work I do is some HTML, which is admittedly fairly
badly done. Despite these limitations, I can usually adapt to any
screen size or layout ranging from tiny Netbook and PDA displays, to
projection screens. Getting a full page view doesn't do much for me.
However, waiting a few days and taking a second look usually causes me
to ask "what was I thinking"?
More seriously, I cheat a bit and have two monitors and two computers
on my desk at home. I have a switch that allows me to put both
monitors on a dual display video card on the main machine. That's
very useful if I want a huge workspace. I don't used it often, but
when doing antenna design and 3D modeling, it's quite handy.
>A second monitor is invaluable in just about any desktop
>(not just DTP) application. It lets you work in one *full*
>screen while having another (full!) screen for other uses
>(e.g., floating pallets for image editing, "text" that
>you are copy/pasting into the actual application, a OCB
>schematic alongside the PCB *layout* you are working on,
>etc.)
Yep.
>(there are currently six 21 inch LCDs
>awaiting pats in various states of disassembly... this causes
>a fair amount of grief! And, isn't realistic when you have
>pets :< )
You haven't seen my office. 700 sq ft, mostly storage and bakers
racks.
<http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
(scroll horizontally). I wouldn't have room for 6 monitors. In my
case, the danger is not pets. It's visitors. Despite warnings,
visitor always manage to smash into something. No fatalities, so far.
>If I did this for a *living*, I would just keep a spare inverter
>around and hack it into the "bad" display long enough to illuminate
>the display (using a nice "white" test screen) to check for these
>"smudges" before investing much time in the repair.
I do that, but only for testing CCFL tubes. I always seem to forget
to test the assembled panels. Thanks for the reminder.
>> That's the problem. For example, I just bought a DC controller for an
>> HP LaserJet 4200. Big crack on the formatter PCB. I could send it
>> back as defective and get another, or just patch the board and be done
>> with it. I'll probably phone the eBay vendor and see what he has to
>> offer. That's one of the risks of buying obviously used parts.
>
>Exactly. And, if the cost of return postage becomes an issue,
>it might not be economical to even *try* to return it (most
>ebay sellers don't consider the threat of a "negative" to be
>important; especially if they are selling in volume)
Nope. They just threaten to give me a negative review for daring to
suggest they're selling crap and don't honor their alleged warranties.
However, that's only happened once in perhaps 8 years, so I'm not
worried about retaliation. In this case, I called the vendor, who
indicated that I should try the board despite the crack, and see what
happens. If it fails, he'll still honor the warranty. So, I crammed
it into the HP LJ4200 (about 20 connectors) and it worked just fine. I
slopped some epoxy on the crack and will deliver it tomorrow. No need
to return it.
>Only to discover that the inverter's design had been changed
>mechanically. Not only had the connectors to the CCFL's
>been "rendered incompatible", but the board mounting wasn't
>compatible, either!
Yep. Been there and had it happen. It's really ugly inside laptop
LCD displays, where there's little room to maneuver. I just bought a
replacement inverter for a Dell B130 laptop that had exactly the same
part number as the original, but where the mounting hole was moved
about 0.050". I took apart the mounting bracket, filed the hole to
fit and reassembled. 20 minutes totally wasted. Other laptops were
not so easy. I've had to use hot melt glue to secure some inverters.
><frown> Would have been better (from a standpoint of my time)
>had they *both* been defective! ;-)
On the other foot, I have nothing against cannibalism.
>On motherboards, replacing caps is considerably more risky as
>the boards are often 4 (or even 6) layers and often don't
>have thermal reliefs around the caps. Unless it is a particularly
>nice board, I don't bother (you also have no way of knowing if
>the high ripple on those power signals hasn't toasted something
>else in the design.
Yep. I have a Pace desoldering station with a motorized vacuum pump.
It's strong enough to suck the pad off the board if necessary. Some
boards offer some relief around the leads, while others are so tight
as to defy removal. I have a method to deal with caps that's somewhat
non-conventional. I have a cable cutter, with semi-circular cutters,
that I use to chop off the top of the cap near the base. I then
remove what's left of the base, leaving only two leads projecting from
the PCB. I grab a lead with pliers, heat the joint, and pull them
out, one at a time. Works nicely and much better than the Pace
desoldering station.
D Yuniskis
> On Thu, 08 Oct 2009 10:51:39 -0700, D Yuniskis
>
>> moving to make 19" as uneconomical to fix as the 17's have become.
>
> Yep. I just did a quick search using Google Shopping for "19" LCD
> monitor". Quite a few refurbished units for $70 to $100. New for
> about $120 to $150. Not very economical to repair at $75/hr.
And their prices continue to fall. So, you fix one only
to find it "competing" with a new, *warrantied* unit for
roughly the same price.
>> I have a Dell that rotates. But, in order to do so, the display
>> has to be "up" high enough (so the rotating end doesn't wack
>> into the tabletop). This places the display too high for me
>> in my normal usage.
>
> Not mine. However, I made my own out of a swivel plate with detents
> as inspired by:
> <http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/>
> The lazy susan is a bit too crude for me. However, all my office and
> home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide
> screen monitors might seem a bit high, but I've built two of these for
> customers and they loved it. One is a script writer and the other a
> technical editor, which might explain their interest in portrait mode
> displays.
I'd rather wider. I tried a three monitor setup once and
*loved* it. But, my current machine doesn't like having
lots of video cards :-(
>> [N.B. I have been told by folks who wear bifocals that even
>> *my* display height is too high for them to use comfortably;
>> they end up having to tip their heads too far back to bring
>> the screen into the correct portion of the eyeglass lens to
>> focus]
>
> I'm 61 years ancient, wear bifocals, and don't have a problem. That's
> because I don't use the bifocals in front of the screen. I'm
> fortunate and can still use the cheap "reading" glasses without
> correction for computer use. For driving, I need bifocals.
Yes, I think the problem is with folks whose reading and computer
Rx's are different. E.g., I know people with "computer bifocals"
(the near Rx is set for the distance to the screen while the
far is set for "distance") and "regular bifocals" (near Rx is
set for reading with far set for "distance"). Apparently,
trying to read "close up" through the "computer Rx" is where
the problem lies (I once saw a pair of lenses cut with *four*
different regions in each lens -- I guess predating "progressive"
lenses?)
Thankfully, I still only need glasses for distance -- though
reading the markings on some components either requires
bright light *or* a magnifying glass (e.g. reading glasses)
Apparently a consequence of losing "focusing power" with age.
> Plug: Cheap prescription glasses:
> <http://www.zennioptical.com>
>
>> I do a lot of DTP and have found that I can get pretty good
>> performance out of nearly any "large-ish" display. When
>> working on prose, etc. I zoom the image to "fit width".
>> This gives me lots of detail (when you've got 1600 dots
>> to play with :> ) and enough of the page vertically that I
>> can see what I am doing. I only look at full page views
>> when I want to get a feel for the layout of the page,
>> the location of whitespace, etc.
>
> Well, I've been told that I have no writing ability, no aesthetic
> sense, no appreciation of layout styles, and no artistic abilities.
Ha! Sounds like a career in POLITICS should be right up your alley!
;-)
I deliberately started taking on these kinds of work just to try to
develop those skills. Spelling is sometimes a challenge (esp
when it comes to "doubling the final consonant") but there are
tools to help with that :-/
> That's a sufficient to avoid DTP and other forms of real work. About
> the only layout work I do is some HTML, which is admittedly fairly
> badly done. Despite these limitations, I can usually adapt to any
> screen size or layout ranging from tiny Netbook and PDA displays, to
> projection screens. Getting a full page view doesn't do much for me.
> However, waiting a few days and taking a second look usually causes me
> to ask "what was I thinking"?
>
> More seriously, I cheat a bit and have two monitors and two computers
> on my desk at home. I have a switch that allows me to put both
> monitors on a dual display video card on the main machine. That's
> very useful if I want a huge workspace. I don't used it often, but
> when doing antenna design and 3D modeling, it's quite handy.
I have my two primary machines attached to a pair of monitors
with built-in A/B switches. So, I can have both monitors
attached to either machine or one monitor on each. I keep the
keyboard for one machine on the work surface and the other in
a "keyboard drawer" beneath. I find this easier than using a KVM
though, at times, I have a hard time remembering which keyboard
to type on! :-/
>> (there are currently six 21 inch LCDs
>> awaiting pats in various states of disassembly... this causes
>> a fair amount of grief! And, isn't realistic when you have
>> pets :< )
>
> You haven't seen my office. 700 sq ft, mostly storage and bakers
> racks.
> <http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
<jealous> ;-)
I work out of a spare bedroom for "head stuff" and commandeer
appropriate floor space as needed (and usually incur much
wrath in doing so!). I think it helps me keep things from
getting out of control and ending up living in a "cave".
> (scroll horizontally). I wouldn't have room for 6 monitors. In my
> case, the danger is not pets. It's visitors. Despite warnings,
> visitor always manage to smash into something. No fatalities, so far.
Visitors you can at least vent your anger on (even if you do
it privately after they depart). With pets, you really can't
blame them for their actions -- the fault lies squarely with *you*!
<frown>
>> If I did this for a *living*, I would just keep a spare inverter
>> around and hack it into the "bad" display long enough to illuminate
>> the display (using a nice "white" test screen) to check for these
>> "smudges" before investing much time in the repair.
>
> I do that, but only for testing CCFL tubes. I always seem to forget
> to test the assembled panels. Thanks for the reminder.
Well, *I* haven't learned that lesson, yet! :< But, again,
if I was doing this "for real", I would set things up more
efficiently (I repair them for a local charity so I can't
really invest much time/space in this)
>> Only to discover that the inverter's design had been changed
>> mechanically. Not only had the connectors to the CCFL's
>> been "rendered incompatible", but the board mounting wasn't
>> compatible, either!
>
> Yep. Been there and had it happen. It's really ugly inside laptop
> LCD displays, where there's little room to maneuver. I just bought a
> replacement inverter for a Dell B130 laptop that had exactly the same
> part number as the original, but where the mounting hole was moved
> about 0.050". I took apart the mounting bracket, filed the hole to
> fit and reassembled. 20 minutes totally wasted. Other laptops were
> not so easy. I've had to use hot melt glue to secure some inverters.
Ouch. Owing to my time limitations, I am pretty reluctant about
investing much "special effort" in fixes that aren't relatively
straightforward. If I was *paid* for my time, I might think
otherwise. Or, if the repair was for my own personal use.
Otherwise, if I can't make it work without re-engineering the
fix, it goes in the recycle pile...
>> <frown> Would have been better (from a standpoint of my time)
>> had they *both* been defective! ;-)
>
> On the other foot, I have nothing against cannibalism.
Of course! I was originally *thrilled* with the idea that I
could make a quick fix just by stealing parts from one for
the other. A real "no-brainer". Hence the disappointment
when I saw the *arbitrary* changes they had made in
manufacturing... :<
>> On motherboards, replacing caps is considerably more risky as
>> the boards are often 4 (or even 6) layers and often don't
>> have thermal reliefs around the caps. Unless it is a particularly
>> nice board, I don't bother (you also have no way of knowing if
>> the high ripple on those power signals hasn't toasted something
>> else in the design.
>
> Yep. I have a Pace desoldering station with a motorized vacuum pump.
> It's strong enough to suck the pad off the board if necessary. Some
> boards offer some relief around the leads, while others are so tight
> as to defy removal.
Exactly. I have actually deliberately laid out some boards
like this to discourage "amateur" repairs. Really obvious
when someone lifts a pad because they weren't prepared to deal
with a board laid out with such fine-line rules...
> I have a method to deal with caps that's somewhat
> non-conventional. I have a cable cutter, with semi-circular cutters,
> that I use to chop off the top of the cap near the base. I then
> remove what's left of the base, leaving only two leads projecting from
> the PCB. I grab a lead with pliers, heat the joint, and pull them
> out, one at a time. Works nicely and much better than the Pace
> desoldering station.
I usually find that the thermal mass of the tip I am using
(at the time) is just not enough to overcome any big ground
planes, etc. And, rather than wait for the tip to cool so
I can swap in something larger, I just move on to the next
candidate. :< Always more broken stuff waiting to be fixed
than there is time available to fix it! (and it sure looks
like the current "lack of quality" will be with us for quite
a while!)
JW
wrote in Message id: <hv0tc55o6p5aumg10...@4ax.com>:
><http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
Those scopes look ancient! :)
Jeff Liebermann
They work. There's another pile of scopes at home including some that
are waiting for me to find time to repair:
<http://802.11junk.com/jeffl/pics/home/slides/BL-shop5.html>
Hmmm... that's an old photo that only shows about 1/3 of the pile. I
guess my test equipment collection qualifies as a 1970's technology
museum, but it's quite adequate for what I need. I'm currently
considering a USB oscilloscope, so some of the old scopes may
eventually be retired.
Jeff Liebermann
<not.goi...@seen.com> wrote:
>I'd rather wider. I tried a three monitor setup once and
>*loved* it. But, my current machine doesn't like having
>lots of video cards :-(
I bought several ATI 2 port PCIe video cards. The county uses Matrox
video cards in their emergency dispatch center to run up to 4
monitors. However, why stop at 3 monitors:
<http://www.wideview.it/wideview.htm>
<http://www.wideview.it/pictures.htm>
>Yes, I think the problem is with folks whose reading and computer
>Rx's are different. E.g., I know people with "computer bifocals"
I can see that if they're transcribbling from notes or have to look at
their fingers when typing. Seeing the screen is not a problem because
it's fixed distance. However, the keyboard and copy might be anywhere
between about 12" to 36". That's a good application for progressive
lenses. Learning to type better and purchasing a copy stand might be
alternatives. Fortunately, I can type at about 30 mistakes per minute
without looking at the keyboard, so single vision is adequate for me.
>Thankfully, I still only need glasses for distance -- though
>reading the markings on some components either requires
>bright light *or* a magnifying glass (e.g. reading glasses)
>Apparently a consequence of losing "focusing power" with age.
Yep. Same problem. I have a Maglite for exactly that purpose. The
depth of field for my eyes increases when the pupil narrows under
bright lights.
>> Plug: Cheap prescription glasses:
>> <http://www.zennioptical.com>
>> Well, I've been told that I have no writing ability, no aesthetic
>> sense, no appreciation of layout styles, and no artistic abilities.
>
>Ha! Sounds like a career in POLITICS should be right up your alley!
Nope. I tried to get elected to the local water board and failed. I
also have some bad habits and strange appearance that apparently
affects my abilities to get elected:
<http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html>
(Give it a few seconds to load).
I also tend to go in circles:
<http://www.LearnByDestroying.com/panorama/jeffl.htm>
(Give it time to load. Then move the mouse around the photo).
>> You haven't seen my office. 700 sq ft, mostly storage and bakers
>> racks.
>> <http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
><jealous> ;-)
That was when it was clean. I'll post a current photo when I get to
the office in a few daze. Incidentally, I've been at the same
location since about 1990, which might explain the accumulation of
junk.
>Of course! I was originally *thrilled* with the idea that I
>could make a quick fix just by stealing parts from one for
>the other. A real "no-brainer". Hence the disappointment
>when I saw the *arbitrary* changes they had made in
>manufacturing... :<
That's not unusual. If you look carefully, the two parts were
probably made by different vendors (both probably working from the
same drawings but making different mistakes). Manufacturers like to
have a single model number maintained as long as possible, even though
the guts change radically. That's so they don't have a deluge of
credit returns and restocking from their own dealers every time a new
and improved model appears. That's very common in the wireless router
business. For example, the Netgear WGR614 and Linksys WRT54G have 9
and 8 different hardware mutations respectively. Unless you know the
trick, it's almost impossible to tell which version without ripping
open the box. LCD monitors are not that bad, but close. Subtle
variations in model numbers (usual a suffix) indicate radical
variations in vendor and internals.
>Exactly. I have actually deliberately laid out some boards
>like this to discourage "amateur" repairs. Really obvious
>when someone lifts a pad because they weren't prepared to deal
>with a board laid out with such fine-line rules...
Never attribute to malice that which is adequately explained by
incompetence.
>> I have a method to deal with caps that's somewhat
>> non-conventional. I have a cable cutter, with semi-circular cutters,
>> that I use to chop off the top of the cap near the base. I then
>> remove what's left of the base, leaving only two leads projecting from
>> the PCB. I grab a lead with pliers, heat the joint, and pull them
>> out, one at a time. Works nicely and much better than the Pace
>> desoldering station.
Next opportunity, try it my way. Being able to eliminate the
cazapitor as a heat sink, and having access to both sides of the lead,
is a big plus. Even the big ground plane sinking doesn't seem to be
as bad with the mass of the cazapitor gone.
D Yuniskis
Good scopes never die! :> I still long for a Tek 454 (which
probably also qualifies as ancient but is more than adequate
for my nominal "analog" needs!). And, I groan when I think
about how many tek probes I gave away over the years :<
(most of my work is digital so I am far more interested in
the "micro hooks/grabbers)
D Yuniskis
> On Thu, 08 Oct 2009 21:45:11 -0700, D Yuniskis
>
>> *loved* it. But, my current machine doesn't like having
>> lots of video cards :-(
>
> I bought several ATI 2 port PCIe video cards. The county uses Matrox
The machines that I am currently using are strictly PCI
(i.e., not PCIe, x, AGP, etc.) so I have limited choices for
video cards. And, most of the slots are already full:
- USB2
- Wide SCSI
- Wide Differential SCSI
- Narrow SCSI
- "sound"
- Firewire
so adding a video card (even a dual-headed card) means losing
something else :<
> video cards in their emergency dispatch center to run up to 4
> monitors. However, why stop at 3 monitors:
> <http://www.wideview.it/wideview.htm>
> <http://www.wideview.it/pictures.htm>
>
>> Yes, I think the problem is with folks whose reading and computer
>> Rx's are different. E.g., I know people with "computer bifocals"
>
> I can see that if they're transcribbling from notes or have to look at
Exactly. If you have written material that you need to consult,
you're screwed. I'm lucky because my interactions are usually
"original works" (so the "source" is in my head someplace)
*or* I can have the "other documents" (e.g., datasheets) open
on another monitor to consult -- instead of having to refer
to paper.
> their fingers when typing. Seeing the screen is not a problem because
> it's fixed distance. However, the keyboard and copy might be anywhere
> between about 12" to 36". That's a good application for progressive
> lenses. Learning to type better and purchasing a copy stand might be
> alternatives. Fortunately, I can type at about 30 mistakes per minute
> without looking at the keyboard, so single vision is adequate for me.
>
>> Thankfully, I still only need glasses for distance -- though
>> reading the markings on some components either requires
>> bright light *or* a magnifying glass (e.g. reading glasses)
>> Apparently a consequence of losing "focusing power" with age.
>
> Yep. Same problem. I have a Maglite for exactly that purpose. The
> depth of field for my eyes increases when the pupil narrows under
> bright lights.
Ah, I never thought of it in those terms!
I have a pair of reading glasses with small LED lamps
attached to each temple. I use them in lieu of a magnifying
glass (much more convenient -- unless you only need to
look at something *once*). If I am in a darkened area
(like trying to read the connector designations on the
back of a PC *under* my work table), then I flip on the
LEDs for more illumination.
To work on boards, I have a 70X (?) B&L stereomicroscope.
>>> Plug: Cheap prescription glasses:
>>> <http://www.zennioptical.com>
>
>>> Well, I've been told that I have no writing ability, no aesthetic
>>> sense, no appreciation of layout styles, and no artistic abilities.
>> Ha! Sounds like a career in POLITICS should be right up your alley!
>
> Nope. I tried to get elected to the local water board and failed. I
> also have some bad habits and strange appearance that apparently
> affects my abilities to get elected:
> <http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html>
> (Give it a few seconds to load).
My browser isn't configured for animations (since those are usually
"ads" -- why waste CPU cycles on something I don't care to see? :> )
> I also tend to go in circles:
> <http://www.LearnByDestroying.com/panorama/jeffl.htm>
> (Give it time to load. Then move the mouse around the photo).
>
>>> You haven't seen my office. 700 sq ft, mostly storage and bakers
>>> racks.
>>> <http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
>> <jealous> ;-)
>
> That was when it was clean. I'll post a current photo when I get to
> the office in a few daze. Incidentally, I've been at the same
> location since about 1990, which might explain the accumulation of
> junk.
I have found that the adage of junk accumulating to fill
available space is true. So, I severely restrict the "available
space"! (clever, eh? :> ) Living in the DSW means you
can't store anything in anyplace *other* than "living area".
So, that means only "inert" things (cables, mechanical
parts, etc.) can be stored in the garage; everything else
has to fit in the office or under a bed or in a closet.
This makes space a premium. I think there are 10 or 11
computers running here (different operating systems,
purposes, etc.) along with 7 or 8 printers (different
capabilities ranging from "postcard printers" to
"wide format"), three plotters (various sizes), three
different scanners (up to B size) -- plus various other
special purpose peripherals.
You learn to get the most out of everything you have
lest you find yourself needing something *else*! :>
>> Of course! I was originally *thrilled* with the idea that I
>> could make a quick fix just by stealing parts from one for
>> the other. A real "no-brainer". Hence the disappointment
>> when I saw the *arbitrary* changes they had made in
>> manufacturing... :<
>
> That's not unusual. If you look carefully, the two parts were
> probably made by different vendors (both probably working from the
> same drawings but making different mistakes). Manufacturers like to
Dunno. The two monitors in question have already been
recycled.
> have a single model number maintained as long as possible, even though
> the guts change radically. That's so they don't have a deluge of
> credit returns and restocking from their own dealers every time a new
> and improved model appears. That's very common in the wireless router
> business. For example, the Netgear WGR614 and Linksys WRT54G have 9
> and 8 different hardware mutations respectively. Unless you know the
> trick, it's almost impossible to tell which version without ripping
> open the box. LCD monitors are not that bad, but close. Subtle
> variations in model numbers (usual a suffix) indicate radical
> variations in vendor and internals.
That seems to be particularly true of the Dell monitors
(which is where this thread started)
>>> I have a method to deal with caps that's somewhat
>>> non-conventional. I have a cable cutter, with semi-circular cutters,
>>> that I use to chop off the top of the cap near the base. I then
>>> remove what's left of the base, leaving only two leads projecting from
>>> the PCB. I grab a lead with pliers, heat the joint, and pull them
>>> out, one at a time. Works nicely and much better than the Pace
>>> desoldering station.
>
> Next opportunity, try it my way. Being able to eliminate the
> cazapitor as a heat sink, and having access to both sides of the lead,
> is a big plus. Even the big ground plane sinking doesn't seem to be
> as bad with the mass of the cazapitor gone.
I'll *try* to keep it in mind -- but expect to forget it! :>
(I've been changing the oil in my vehicles for decades and I
always remember to put on the nitrile gloves *after* I am
finished :-(
msg
> Jeff Liebermann <je...@cruzio.com>
>> I've
>> also managed to get electrocuted several times, mostly due to haste,
>> sloppiness, clip leads, or all the aformentioned.
>
> Not "electrocuted",but shocked.
> "electrocution" is to KILL with electricity. Since you're still posting,you
> aren't killed. ;-)
Unless he is one of the new fast walking zombies (thanks Two and a Half Men).
Michael
propman
> alternatives. Fortunately, I can type at about 30 mistakes per minute
> without looking at the keyboard, so single vision is adequate for me.
LOL! We must have had the same typing tutors!
Plain...@yahoo.com
The large (rectified mains filter) is handling 120 Hz ripple (and the
pulses from the SMPS). The filter caps on the secondary are handling
100 KHz or greater ripple. As I understand the problem, the ripple
current will cause heating (duh!), which will cause the ESR to rise,
causing more heating, until eventually a poorly made cap will vent.
The mains filter cap has several advantages - much lower current and
much more surface area to dissipate the heat.
PlainBill
Samantha
found all the tabs with the help of a small spackle knife. Found the
buldging 1000uf 16v capacitor. Found a replacement on an old board from
a TV and swapped the two. I have the monitor on and the test pattern up
now. Have let it set for about an hour now. Will leave it for a few
more to make sure nothing else happens...
Want to give you all a lot of thanks for the help. I probably would
have stumbled around inside there for quite awhile before I really
figured out how it work.
Knowing how something breaks (common failures) is invaluable when trying
to troubleshoot something.
Thanks to all!!
S.
Samantha
<4493aa23-cd53-4726...@p23g2000vbl.googlegroups.com>,
Jake <mechani...@gmail.com> wrote:
> On Oct 6, 6:19�pm, Samantha <saman...@comcast.net> wrote:
> > I have a Dell E152FPc Flat screen Monitor 15" that goes black after
> > about a second after it is powered on. �The Green power light stays on
> > and the color bar test pattern is there if you stick a flash light up to
> > it. �
> >
> > I have never had one of these apart and am not really sure what I am in
> > for. �Just looking at it, I don't see any obvious way to take it apart.
> >
> > There are some screws to take off the stand, but after that I am not
> > sure.
> >
> > Anybody ever take one of these apart and fix it?
> >
> > Would greatly appreciate any help.
> >
> > Thanks so much!!!
> >
> > S.
>
> I recently repaired 3 E153FP's, which I believe are virtually
> identical.
>
> The problem was a 1000uF, 16 volt capacitor, used for the power
> supply. It had excessively high ESR, and I am assuming it caused
> excessively high ripple voltage which was making the LCD's control
> circuitry wack out (that's my very technical description of what I
> thought was going on, ha ha). I replaced the same cap on all 3 - It
> was easy to identify, about the largest cap on the board, the PCB
> material was darkened around it, and the top of the cap was bulged.
>
> Good luck! The 3 I fixed had the exact same symptom you describe, and
> have been back in service for about 3 months with no further problems.
>
> -Jake
That is the same same with this one. Found a suitable replacement and
done. Thanks!!
Jamie
Maybe you might already be aware of this ? but I'll spit it out
in case some one else here may benefit from it.
When ever replacing caps found bad like that, in inverter supplies,
it's a good idea to make sure you use computer grade or some sort of
low ESR types. This is one of the problems that plague these types of
circuits and high ESR just pushing it along faster making the cap run
warm.
Jim Yanik
47B939.171...@news.giganews.com:
Congratulations! it feels good,doesn't it?
--
Jim Yanik
jyanik
at
localnet
dot com
D Yuniskis
> Took the time today to open that monitor. It went pretty smoothly,
> found all the tabs with the help of a small spackle knife. Found the
> buldging 1000uf 16v capacitor. Found a replacement on an old board from
> a TV and swapped the two. I have the monitor on and the test pattern up
> now. Have let it set for about an hour now. Will leave it for a few
> more to make sure nothing else happens...
Chances are (?), the "replacement cap" was not a high temperature
device (though it might be... depends on where you cound it in
the TV). You really want 105degree (C) devices as they tend
to be higher reliability in these applications. Otherwise,
you'll be replacing *it* soon!
Also, check the manufacturer on the (bad) cap. Chances are there are
a few other caps made by the same manufacturer on that board.
Often best to just replace them all (I realize you are unlikely
to find replacements for all of them on that "TV board" -- but,
if you have to order a hi-temp cap you might as well order
the rest of them if you want to keep the display running for
any length of time) Omit the 400V cap as it seldom fails.
Panasonic FM series caps seem to be a good tradeoff between
cost and reliability. DOUBLE CHECK COMPONENT HEIGHTS/WIDTHS
so you don't end up ordering things that won't fit!
> Want to give you all a lot of thanks for the help. I probably would
> have stumbled around inside there for quite awhile before I really
> figured out how it work.
>
> Knowing how something breaks (common failures) is invaluable when trying
> to troubleshoot something.
Exactly. I use repair experiences to guide me in determining
what to avoid when *designing* stuff.