60 inch RCA projection TV next steps after failure of EPROM being the fix

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For all of you that provided me with feedback on my 60 inch TV.
Thanks.

Today the technician came and changed the EPROM and as you-all pretty
well told me, it was not the EPROM. After I mentioned the coolent
problem, he homed in on that and found a couple of drops and after that
pretty well gave up saying that the board was as good as gone. Since
now the TV is so much garbage unless I find an answer to this, I tore
into it tonight. Yes, there is a drop or two (and a drop or 2 is not
an exaggeration). There is a drop or two on a wire and some evidence
in of it (a slight film on the top surface of the components) in the
vertical deflection section on the right rear side of the main board).
There is NO evidence that any corrosion has started anywhere I can see
on the main board. I took the main board out of the plastic tray and
examined both sides with high power magnifiers and the circuitry looks
clean and bright.

Very interesting finding, however. The large chip behind the tuner
(UT16201) was soldered in by someone and there is a lot of solder flux
around the chip. It appears that their was some circuit damage when it
was replaced. Now, I have never had a repair person in to look at the
TV, so this must have happened at the factory (TV bought in June of
1998).

Anyway, I am cleaning the underside of the board carefully with some
circuit board cleaner in the area of the UT16201, the EPROM and the
vertical deflection section as well as the Micro (U13101) in the rear
of the main circuit board. I assume that the possibility of conductive
glue mentioned around the clock and data lines described in the
previous postings would be in this area (described as the service micro
on the board).

I will now reassemble the TV and try it out. If what I have done does
not demonstrate improvement, do you-all think it wise to remove the
chassis and find a knowledgeable repair person to look at it? How do I
find THAT person? This outfit I used was listed as a factory
authorized repair service.

Again, for reference, the service # is P60812BLLG2. The number on the
metal tag
on the main board is CTC195A JR47344C9D. The # on the digital
convergence board is PTK195AC 0 7355K2D
A number below that (which looks like a serial number) is
59835735521092RWB-TCE.

Thanks again everyone for your comments and suggestions.

 

[John-Del]

You need to fix the leak first, or this will be a never ending problem.
Here is a segment of a post I made about how I handle these once the
lead is gone:

Subject: Coolant leaks, a tip and a question

Date: 10/11/04 10:47 PM Eastern Daylight Time
Message-id: <20041011224726.06333.00001300@mb-.

Now the question: Coolant leaks seem to be more common these days. What
methods
do "y'all" use to clean the PCBs ?

While it's enormously time consuming, I remove any component that could
trap
liquid. I remove all transformers, chokes, tunable cans, etc. I then
remove
all connector sockets which trap liquid underneath. I soak the board
in
hot water, and clean with a solution of Parson's kitchen cleaner (uses
ammonia)
and water, and scrub the board clean. I then dry in a hot box (big
cardboard
box with a hole at one end to push a hair dryer in) and reassemble. Any
component (like transformers) that has trapped the coolant needs to be
replaced. While a pain in
the ass, at least I know that any further problem isn't from coolant
contamination. If it still doesn't work, I just repair as any other
defect.