I'd be looking for a coolant leak. About half of the problems that we have
seen on the 195 chassis have been related to coolant on the boards. It can
be hard to find but the first thing to look for is a dark goo on top of the
board.

Leonard

wrote in message
oups.com...
This is a continuing saga of a 60 inch rear projection RCA TV. It has
a chassis number of
PTK195AC and is model P60812BL. I have now had a repair technician
over and it worked like a charm while he was here and for a couple of
hours after he left. Then it returned to the absolutely black picture
it had when the problem first surfaced a few days ago. The repair
technician feels he should change the EPROM. Can an EPROM problem
result in NO output from a projection tube?

This is the sequence of events.

The other day one minute it was working perfectly (as it has for 8
years). All of a sudden I walked into the room and the screen is black
(none of the projection tubes are putting out any light).
Turning it off, using the DVD and many other attempts to get a picture
failed. I let it stay off for a while, then turned it on. It would have
a
picture for a short time that looked like an old 60's horizontal hold
problem with a partial, shrunken picture. After a while the picture
would be stable enough to be able to read letters, but totally
distorted. I was afraid to leave it on long figuring I might stress
the conditon. I called a repair technician and he came over today.

The repair technician went into the service mode of the TV and changed
a number of parameters stored in the EPROM and finally got it looking
as good a new. He also used an external alignment generator and the
grid looked straight and proper. Colors were true and bright. As I
said, this lasted about a couple of hours after he left and then the
screen went black (non of the projection tubes are generating any
output) which is exactly the condition that happened when the problem
first started. The filaments in the projection tubes glow and the
sound and power-on sequence is just as it should be. So far I have
not been able to get any type of picture back. I tried to get into a
service mode per the instructions to push the menu power and +vol
button. I have no picture and that did not give me one to be able to
see any setup procedure. Again, would a bad EPROM result in NO output
from the projection tubes?


Anyone have any ideas where to start?