Projection TV Fluid leak
re...@my-deja.com
bought a new because the picture was blury and the tunner is supose to
be bad, he used a vcr as his tunner. enough background
After getting it to my house I pull the reflector off the front and
noticed fluid. After a closer look I noticed that the plastic overflow
resivor was lose and fluid had leaked out of the middle tube. What is
this fluid, where can I get some and how full do I fill it?
Is this a fluid that should be changed, does it get dirty? I removed the
lens and can see a very small brown streak like dirt or something in
the coolant had heated up. Is there maintenance procedures for these
TVs?
What is the best way to clean the lens and mirror, they have a nasty
film like smoke residue.
Thanks
Rodney
Sent via Deja.com http://www.deja.com/
Before you buy.
Wild Bill
on this PTV.. you might be at the beginning of a research project that may
require a lot of knowlege.
You didn't specifically state how familiar you are with this type of
equipment, but the types of questions would lead me to believe that you
aren't very familiar with PTVs.
You can find a lot of answers to these questions from knowlegable servicers
by searching the archived messages of the S.E.R. newgroup with Deja's Power
Search feature. Keywords to enter are Projection, PTV, RPTV, Coolant, etc."
or the brand/model number.
http://www.deja.com/home_ps.shtml
Enter sci.electronics.repair in the Forum box.
Web searches for projection TV repair information will provide more info
http://www.dogpile.com/index.html?nocookie
If you're not completely familiar with the safety risks involved in working
with high voltage circuits or near CRTs, there are important safety
precautions in the S.E.R. FAQ
http://www.repairfaq.org/REPAIR/
A few precautions..
Liquids in/on high voltage circuits are hazardous for you and the circuits.
The liquid coolant is poisonous, and requires special handling.
The coolants often have bacterial growths suspended in them, and sticking to
the CRT face.
Low or improper coolant will damage the CRTs.
Scratching the mirror or the front lenses will degrade the picture quality.
The mirror is most likely a first surface mirror, which shouldn't be cleaned
like an ordinary mirror.
The streak(s) may be burn marks in the CRTs, and if so, are permanent.
The cost of a replacement CRT is often more than $200 US.
cheers
WB
...........
re...@my-deja.com wrote in message <8odu8s$9c6$1...@nnrp1.deja.com>...
David Kuhajda
We had someone bring in one of these NAP (one with the power supply and tuner on
the board at the back bottom of the set) sets he tried doing the coolant job
himself. He spilled crt coolant on the main pcb with the power supplies and then
tried running it in the dishwasher to clean it all off. Needless to say the board
was destroyed and NAP wanted over $620 our cost as no dud would be allowed.
Needless to say he declined our $800 estimate which was very generous given the
cost of the board and the time that would have been required to clean the set up.
David
JURB6006 wrote:
> You really ought to post the numbers off that thing, and the make. I have
> several good used projo CRTs I'm willing to sell for alot less than a new one.
>
> And, quite important : how old is old ?
>
> You can get a good picture on some units as old as 17 years, not on others.
>
> I bet it's an NAP built unit, look for a PTV # , I say this because you
> mentioned a tuner problem. They were common. Probably a PTV340 or so. If so,
> they usually didn't have super sharp focus, but their tubes are usually good
> enough for a decent resolution and good color rendition.
>
> Let me put it this way, if you are adept enough to rebuild a 4 barrel
> carberator and have it work right, you can probably handle this coolant job.
JURB6006
re...@my-deja.com
#RSK435 AK02. In the last couple of days I have removed the heat
transfer fluid and cleaned the tubes (tv was not charged at that time).
Fluid in green and blue crts were extremly cloudy. Ordered heat
transfer fluid from MCM electronics, is suppose to be the same as what
Phillips uses. I should receive the fluid tonight. I also suspected
fluid may have leaked onto main board, so I removed main board and used
electrical cleaner and compressed air to clean it. All has been
reassembled to the point of putting the fluid in, everthing is working
ok. Powered up set everything worked fine, cant believe the difference
in the Green and Blue crts with old fluid out and cleaned. Will
reassemble rest after installing new fluid. I am replacing fluid in all
three crts.
In article <8odu8s$9c6$1...@nnrp1.deja.com>,
David Kuhajda
apart and make sure none of the metal is showing in the coolant area. If ti
is the metal will corrode into the fluid quickly, 3 months, and make it
cloudy again.
I have had very good luck with the flat black spray paint rated for high
temperature use that you can get in most auto parts stores. I clean the
corroded metal areas, rough it up with steel wool, spray paint a nice thin
coat of the paint, bake it on in my oven at home per the paints
instructions, let it fully cure over a weeks time before adding the
coolant. Of course only the rubber gasket is off and it gets baked at low
temperature.
When reassembling, you want to completely clean out the gasket seal and
reseat it with a new seal if possible, or put a very small amount of the crt
coolant to wet the seal and make very certain it is seated properly.
Do not run the tv without the coolant installed as this will damage the
crt's. A few seconds to make sure the set works is ok, but not any longer.
David
re...@my-deja.com
Now I am interested in repairing/replacing the tunner. It seems to
always be on the same channel and will not find any channels when
scanning for cable channels. Is there somewhere that I can order parts
direct. I really don't want to go through any of the local repair
shops. They don't seem interested in ordering parts they won't be
replacing.
In article <39ADAFAF...@locl.net>,
Andy Cuffe
>
> I am finished with the crts. I can't beleive how nice the picture is.
> Now I am interested in repairing/replacing the tunner. It seems to
> always be on the same channel and will not find any channels when
> scanning for cable channels. Is there somewhere that I can order parts
> direct. I really don't want to go through any of the local repair
> shops. They don't seem interested in ordering parts they won't be
> replacing.
>
This is a VERY common problem with late 80's Philips made TVs. It's
caused by an IC in the tuner (mounted on a small sub board inside the
tuner). The original IC was made by siemens, but crosses to a Philips
IC. I don't remember the numer off hand, but searching for the number
of the old IC on dejanews should lead you to a post with the new part
number. It requires very good soldering skills to replace and a temp
controlled iron with a long thin tip is a must. Replacing the entire
tuner will also fix the problem, but costs about 10 times as much.
--
Andy Cuffe
balt...@psu.edu
ae2...@wayne.edu
many questions I plan on asking that'll cause you to strain to come down
to my level.
I was interested in this thread because i have a rear-projection TV, a
sony videoscope RVP-460 from 1983. Considering its age and that I found
it in a closet presumably left on for several years, it works pretty
good. However it doesn't want to converge very well. You can pull it in
on one corner via the front panel controls, but then the other side is
hopelessly separated. I usually just split the difference and live with
it. I had thought about probing around in the back of it though, to see
if anything could be done to straighten it out. (I know, you're probably
all scared thinking about how I probably know just enough to be dangerous.
deal with it :)
So here's my questions:
1. What is the need for this cooling fluid you speak of? Do all
projection TVs use it? where does it go, is there a cooling jacket around
the CRT's glass envelope? Is it circulated by a pump or anything?
2. Does it need to be periodically changed? If so, what is the change
interval? Someone was talking about bacterial growth in the fluid, and
that it can cause damage to components if it comes in contact with them.
What should I know about this fluid? Is it caustic? Does used fluid
constitute a biohazard? How difficult is it to R&R the fluid?
thanks in advance.
kevin spears
Andy Cuffe
>
> You'll all have to forgive my ignorance, but this will be the first of
> many questions I plan on asking that'll cause you to strain to come down
> to my level.
>
> I was interested in this thread because i have a rear-projection TV, a
> sony videoscope RVP-460 from 1983. Considering its age and that I found
> it in a closet presumably left on for several years, it works pretty
> good. However it doesn't want to converge very well. You can pull it in
> on one corner via the front panel controls, but then the other side is
> hopelessly separated. I usually just split the difference and live with
> it. I had thought about probing around in the back of it though, to see
> if anything could be done to straighten it out. (I know, you're probably
> all scared thinking about how I probably know just enough to be dangerous.
> deal with it :)
There are some dynamic convergence controls inside the set somewhere.
Look for a board with several rows of pots on it. They will allow you
to adjust the widht and height of the red and blue seperately as well as
a number of other geometry adjustments. Assuming the convergence
circuit is working, you should be able to get within about 1/4"
everywhere except the extreme corners.
> So here's my questions:
>
> 1. What is the need for this cooling fluid you speak of? Do all
> projection TVs use it? where does it go, is there a cooling jacket around
> the CRT's glass envelope? Is it circulated by a pump or anything?
It's there to remove the heat generated by the screens of the small CRTs
and also optically couples the CRT to the first lens. In fact, the
fluid becomes the first lens in some PTVs. If it uses it, it will be
over the screens only, not the entire CRT. Some older PTVs used a gel
pad sandwiched between the CRTs and the lenses. Before that they used
forced air cooling, or just convection. That worked fine, but the CRTs
would get dirty from the air flowing over them.
> 2. Does it need to be periodically changed? If so, what is the change
> interval? Someone was talking about bacterial growth in the fluid, and
> that it can cause damage to components if it comes in contact with them.
> What should I know about this fluid? Is it caustic? Does used fluid
> constitute a biohazard? How difficult is it to R&R the fluid?
I've seen 20 year old PTVs with crystal clear fluid and 8 year old TVs
with cloudy fluid. There will be no doubt if it needs to be changed.
When the fluic gets cloudy, one or more colors will become so flggy that
you can't even see the convergence cross. How difficult it is to change
varied a lot from TV to TV. Some (like magnavox) are easy to
disassemble and clean. They even sell replacement fluid (at about 6
times the cost of the generic). Some Sony CRTs are siliconed together
and have to be cut apart. This takes several hours per tube and is very
messy. As far as I know, Sony recommends replacement of the entire CRT
if the fluid goes cloudy. There seem to be two common reasons for it to
go cloudy. Magnavox TVs have some kind of bacteria that only likes blue
and green light. I don't know where it comes from, or what can be done
to stop it from growing. I've never seen bacteria in a set that had the
fluid replaced, but it takes a while to grow. Sony had a problem in the
mid 80's where the fluid would actually eat into the metal housing which
caused the fluid to go cloudy. In this case, you need to seal the pits
in the housing, or it will quickly go cloudy again. I have never seen
cloudy fluid in any other brand and I've only ever seen bacteria in
magnavox TVs. The fluid is just car anti freeze without the coloring.
Don't drink it and you'll be fine. If any gets on the board, wipe it
off with a damp cloth.
> thanks in advance.
> kevin spears
>
--
Andy Cuffe
balt...@psu.edu