How to open composite monitor //e
hmbrew
I have an "Applecolor (tm) composite monitor //e" model no. A2M6021.
I need to open it to replace the caps so it will stop squealing.
How do I open it? I have removed all 6 screws that I can find. The two
halves separate by about an inch, but it feels like cables inside or
something are preventing me from completely opening it. I have tried
looking inside with a flashlight but cannot see what the obstruction
is. (the opening is too narrow)
Note: if yours has rubber caps over some of the screws, it is not the
same model as this one. That model is the 6021-x.
Thanks in advance.
Michael Black
I've never seen the model up close. But if there's an indentation in
the back that can act as a handle, that's a possible place for screws.
Also, the Apple monitor I do have had a screw in the middle of the back,
I guess where the power cord enters. Other monitors I've opened often
have a screw in the middle of the back, acting as support for the back of
the circuit board.
Michael
hmbrew
> On Tue, 29 Dec 2009, hmbrew wrote:
> > Hello all,
>
> > I have an "Applecolor (tm) composite monitor //e" model no. A2M6021.
>
> > I need to open it to replace the caps so it will stop squealing.
>
> > How do I open it? I have removed all 6 screws that I can find. The two
> > halves separate by about an inch, but it feels like cables inside or
> > something are preventing me from completely opening it. I have tried
> > looking inside with a flashlight but cannot see what the obstruction
> > is. (the opening is too narrow)
>
This model does not have a handle. There is no screw in the exact
middle, but I have removed 2 screws about 4" to either side of the
middle. (on the back)
There were also 2 on the bottom, parallel to the others that go into
the back. These were near the front edge of the monitor.
The final 2 were on the back as well, but near the top.
All of these screws were in plain view, and there are no evident caps
or recesses to hide additional screws.
It's possible that the two halves snap together in a way that is never
meant to be opened. If that is the case, I'll just have to be
innovative.
Peter Watson
news:92e6e3ab-18be-4ec0...@3g2000vbp.googlegroups.com...
> On Tue, 29 Dec 2009, hmbrew wrote:
> > I have an "Applecolor (tm) composite monitor //e" model no. A2M6021.
>
> > I need to open it to replace the caps so it will stop squealing.
>
> > How do I open it? I have removed all 6 screws that I can find. The two
> > halves separate by about an inch, but it feels like cables inside or
> > something are preventing me from completely opening it. I have tried
> > looking inside with a flashlight but cannot see what the obstruction
> > is. (the opening is too narrow)
>
> middle, but I have removed 2 screws about 4" to either side of the
> middle. (on the back)
> There were also 2 on the bottom, parallel to the others that go into
> the back. These were near the front edge of the monitor.
> The final 2 were on the back as well, but near the top.
> All of these screws were in plain view, and there are no evident caps
> or recesses to hide additional screws.
> It's possible that the two halves snap together in a way that is never
> meant to be opened. If that is the case, I'll just have to be
> innovative.
Remarkably, I discovered I still have a copy of the dealer service
procedures manual for the monitor!
That's the good news. The bad news is that it doesn't seem to shed any new
light on the subject. :-(
There's multiple different revisions and models (from different
manufacturer's) but I think I've identified the one you have from your
description of the screws. (Two on the bottom, four on the back.)
After removing the screws, the next steps are:
5. While pushing down on the rear panel with one hand, carefully pull the
rear cover up until it clears the CRT board.
6. Pull the AC power cord through the opening in the rear cover. Set the
rear cover aside.
That's it! The two steps refer to a diagram, but it's very simple and really
does nothing to add new info.
I used to do part-time repair work on Apple gear, and while I remember
needing the occasional product opening trick, I don't remember anything
about the //e monitor.
So it really does sound like something's simply "caught" on a cable or
whatever. If it was anything other than a monitor I'd say just wiggle things
a bit harder, but that's not always a good move with CRTs!
I don't know whether Tony D has any better suggestions?
--
Peter Watson
-- Write to MS-DOS disks on the Apple IIgs?
-- Impossible! ;-)
A2Aviator
monitor stand underneath (those models that did), others have two
screws at the joint between the rear and front case halves that are
visible when the monitor is face down, they will be pointing up along
the joint, and there is usually some method of mounting the chassis
near the AC line cord, that holds the cover down as well. Nothing
hidden under feet.
I will say that the feeling you are describing sounds to me like you
have gotten all the screws out from the perimeter but there is one
remaining and thats usually the back panel area.
I'll presume by now you've gotten the thing apart, if not .. post a
picture of the back, as I don't remember exactly what on each monitor
type, but when they are in front of me I have them open in seconds.
There are not phantom clips and similar things on those. Nothing
grasping from the inside. Unless someones played a trick on you and
put glue in the gaps, there's nothing holding anything down but
screws.
hmbrew
figure this out for months. I've peeled off labels and everything, no
more screws.
There is no round part for a monitor stand, it's quite rectangular on
the bottom for sitting on a duodisk drive or something.
As I mentioned before, the two halves come apart by about an inch, but
no more than that. (I'm sure it's not glued)
I'll try to get a picture on here soon, but my camera is currently out
of commission. (I'll borrow one or something)
Silicon Sam
Did you check the 2 screws on either side that hold the power cord
or power plug in?
A2Aviator
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310190654713
..two screws above that panel where the power cord goes in, two at the
top and I recall two somethings on the bottom.
That panel where teh power cord is, stays where it is. The top comes
off the power cord passes through.
There's nothing inside holding anything.
hmbrew
That sounds mostly right. The two "things" at the bottom are screws
pointing towards the front. That sounds like what's supposed to happen
during disassembly.
That is the same monitor I have. I was confused at first because the
title says 2056, but the description says 6021, like mine.
Do you mean to say that the panel that the cord goes through comes off
with the back half and the cord slides through the narrow hole on the
panel? It doesn't want to slide through there, but that might just be
a result of being in there for so long.
Alternatively, do you mean that the back cover comes off leaving the
panel with the cord affixed to the front half of the monitor?
Thanks, it sounds like we're making a little progress here regarding
the assembly's configuration.
Silicon Sam
Yes, the back cover comes off leaving the panel with the cord
affixed to the front half of the monitor. It's been a number of
years since I had one apart, but that should be right.
A2Aviator
line cord stays right where it is. It is a separate piece from the
rear chassis cover. That is actually connected to the logic board
which is secured to the chassis. So if you've not removed those two
screws, this is whats lifting and giving resistance.
There will be a "mail slot" like hole in the rear chassis cover when
you lift it off.
Michael Black
I did reference that, though not as well, in my post. There's something
like that on the Apple III monitor. As I recall, despite the screw(s)
it wasn't obvious until the cover wouldn't come off and I realized I did
have to unscrew that piece.
Michael
hmbrew
Well it must be stuck, because said panel tries to remain attached to
the back cover when I lift it off. Maybe I can solve this with some
well-placed force. (But carefully)
I'm usually excessively nervous about forcing something when I'm
taking stuff apart.
I'll fiddle with it some more when I get home again tomorrow.
A
I tried applying force to free the power cord's panel from the back
cover to no avail.
It's still quite stuck, and I even wonder whether even a blow from a
hammer could free it. I doubt that it is glued, since I got it to
budge slightly (by prying it with a screwdriver). Upon studying the
construction and reading suggestions, I am reasonably confident that I
understand how it is supposed to come apart.
Has anyone heard of one getting badly stuck like this? Any suggestions
before I go "all out" on it?
hmbrew
Oops, I used my other email for the previous post. Anyway, the
previous post was really me. Sorry, having several accounts relaying
messages to each other gets confusing.
Mike Spurgeon
> Has anyone heard of one getting badly stuck like this? Any suggestions
> before I go "all out" on it?
The monitor value is low. It's been days.
Go all out.
hmbrew
Well, after much banging and slamming, I got it open. It appears
undamaged (at least as undamaged as it already was).
I saw enough warning labels to make me take a step back. Everything
from "x-ray shielding may be needed when operating at high-voltage" to
"high voltage, don't touch that!".
Next, I'll take a deep and thorough look at safety precautions for re-
capping it. (ie, discharging everything without electrocuting myself
before I start poking around)
Thanks everybody.
Michael Black
The highest voltage is on what looks like a suction cup on the side of
the picture tube. Shorting that to ground will get rid of the worst,
take a needle, solder a good piece of wire to it, tape the needle to a dry
stick, with the other end of the wire going to the chassis of the monitor.
Slip the needle under the "suction cup" (it really isn't it's just a
rubber disk that well covers the actual high voltage contacts that insert
into a well in the picture tube). If you're lucky, there should be a
spark (I say lucky since it proves that you've properly made contact
with the contacts underneath, but if there's no spark, it could mean
the voltage has already dissipated, or that you didn't make proper
contact).
That discharge of the high voltage on the picture tube will ensure that
you won't get a shock merely by rubbing against the picture tube.
The remaining higher voltages are more likely contained, certainly the
most exposed voltages would be on the bottom of the circuit board.
I can't remember why you wanted to open the monitor, so the potential
dangers depend on whether you actually need to do something to the
circuit board.
Michael
> Thanks everybody.
>
Michael J. Mahon
Now that you have it open, you might try placing it carefully so that
it can be operated with the back off.
Listening carefully may reveal that the sound you hear is just a
result of mechanical play in a ferrite core of the flyback transformer
or the yoke. If so, slight tightening of a clip or screw or application
of some Glyptol lacquer could solve the problem.
Wholesale re-capping is seldom necessary or useful.
-michael
NadaNet and AppleCrate II: parallel computing for Apple II computers!
Home page: http://home.comcast.net/~mjmahon
"The wastebasket is our most important design
tool--and it's seriously underused."
Jeff Blakeney
Michael Black wrote:
> The highest voltage is on what looks like a suction cup on the side of
> the picture tube. Shorting that to ground will get rid of the worst,
> take a needle, solder a good piece of wire to it, tape the needle to a
> dry stick, with the other end of the wire going to the chassis of the
> monitor.
> Slip the needle under the "suction cup" (it really isn't it's just a
> rubber disk that well covers the actual high voltage contacts that insert
> into a well in the picture tube). If you're lucky, there should be a
> spark (I say lucky since it proves that you've properly made contact
> with the contacts underneath, but if there's no spark, it could mean
> the voltage has already dissipated, or that you didn't make proper
> contact).
You might want to add that the monitor should be plugged in to make sure
the ground prong of the power cord, which is connected to the chassis of
the monitor, is actually connected to ground. Otherwise, you might not
discharge anything and might even add a charge to the chassis. Once it
is discharged you can unplug the monitor.
Another option is to connect the wire to ground some other way other
than using the chassis of the monitor. I've used a banana plug on the
end of a wire plugged into the ground prong hole of an outlet to make
that connection before.
sicklittlemonkey
> I saw enough warning labels to make me take a step back. Everything
> from "x-ray shielding may be needed when operating at high-voltage" to
> "high voltage, don't touch that!".
>
> Next, I'll take a deep and thorough look at safety precautions for re-
> capping it. (ie, discharging everything without electrocuting myself
> before I start poking around)
Have a read of this:
"The Truth About CRTs and Shock Danger"
http://lowendmac.com/tech/crt_danger.html
Cheers,
Nick.
hmbrew
Well, my initial reason for taking it apart was to replace those caps.
It's still a possibility if the other things mentioned by Michael
(Mahon) don't work.
Speaking of which, What do those things look like? (Ferrite core,
flyback transformer and yoke) I'm seriously a beginner in all this
stuff. What would I need to tighten and how would I do it? What would
I apply the lacquer to?
Most of my experience is on paper with digital components, rather than
opening old stuff and fixing it.
A2Aviator
likely ..
Watch out.
I've been unloaded on my a Mac Plus and a Tron video game before. I
was taking standard precautions, one hand in pocket, belt line,
whatever, etc., and still had a discussion with said CRT because it
felt I was invading it's turf.
The Tron game was in an arcade during business hours, the screen was
wrapping and the MCP cone phase of the game was very annoying to play
with part of the top wrapping around to the bottom. Very distracting.
It was a very very dry day and I was on the other side of the chassis
from the flyback wire and still got used as a bleed path. The area
near the cup was "leaky".
The Mac Plus jumped at me as I reached past the power supply while I
was setting up to discharge it. The Mac Plus packed a ton more punch
than the Wells Gardner monitor in the Tron game, and the game was on
and running. So the picture could be adjusted in a mirror (which
happened to be a Dragon's Lair laserdisc leaning on the
windowsill. .. )
Michael J. Mahon
> To: Michael Black
> Michael Black wrote:
>
>> The highest voltage is on what looks like a suction cup on the side of
>> the picture tube. Shorting that to ground will get rid of the worst,
>> take a needle, solder a good piece of wire to it, tape the needle to a
>> dry stick, with the other end of the wire going to the chassis of the
>> monitor.
>> Slip the needle under the "suction cup" (it really isn't it's just a
>> rubber disk that well covers the actual high voltage contacts that insert
>> into a well in the picture tube). If you're lucky, there should be a
>> spark (I say lucky since it proves that you've properly made contact
>> with the contacts underneath, but if there's no spark, it could mean
>> the voltage has already dissipated, or that you didn't make proper
>> contact).
>
>
> You might want to add that the monitor should be plugged in to make sure
> the ground prong of the power cord, which is connected to the chassis of
> the monitor, is actually connected to ground. Otherwise, you might not
> discharge anything and might even add a charge to the chassis. Once it
> is discharged you can unplug the monitor.
Actually, this is not so.
The only potential difference that matters is between the anode of
the CRT and the chassis ground (which is what you will be referenced
to as you work on or about the monitor). Earth ground is irrelevant.
You need to discharge the capacitance of the CRT, not discharge any
charge relative to the planet earth. ;-)
Michael J. Mahon
Rather than go into a long discourse, I recommend that you read up
a bit on CRT monitors--Wikipedia might be a good start, but any TV
repair discussion will cover the ground.
You wouldn't pop the hood of your car and start replacing all the
ignition wires without reading up on it, and I wouldn't recommend
doing it with your monitor, either.
Blind replacement of capacitors (or any other component) is actually
a grave risk to the PC board of the monitor, and it is virtually
certain that 90% of the capacitors are as good as the day they were
made. It's always "one bad apple" that causes a problem, and the
repairman's job is to find it and replace it. Shotgun approaches
are often seen as a "quick and dirty" way to fix problems, but they
are never really quick, and they are always dirty. ;-)
Remember, it may not even *be* a capacitor causing the problem!