I have a Proscan 36" Model PS36125 Chassis CTC197CG, made November
1997. I am looking for any service bulletins that may apply to this
chassis. A description of the problem follows. The tuner-on-board
has the single solder point in the middle.

The TV will run fine for several hours (~36 at one point) then shut
itself off for no reason. Sometimes it will shut off then on again
and continue running for hours before shutting off for good. After a
complete shutdown I can turn it on again immediately or have to wait
for a few minutes to a few hours before it the on button responds.
While running, the picture and sound are flawless (no jumping, snow).
I have a one sheet diagram from a CTC197 projection TV that I have
been using to do tests. The 5V, 12V and B+ correspond pretty much to
the listed values and don't fluctuate wildly when I turn the set on or
off. I have have heard on problems involving some SMD caps on the
on-board tuner causing the microprocessor to crash.

This set was apparently repaired while under warranty but the owner
says that the shutdown problem only went away long enough for the
warranty to expire. I noticed the solder on the flyback and SMPS
transformer was retouched. I checked the board over and there is no
other sign of bad solder anywhere. Any advice is appreciated. Thanks

Resolder the little coil between the HDT and the HOT. You usually cannot see
the bad connection. I found it the first time with a scope.

Be happy it didn't blow the HOT, sometimes they do, sometimes they don't.

JURB

JURB