One special note. When you remove the old convergence ic's, completely
remove the old heatsink compound and reapply an air tight thin coating of
heatsink compound to the new ic's. Make sure they are firmly attached to
the heatsinks.

Be very careful not to damage or overheat the circuit boards when removing
the old parts. Sony boards tend to be easily damaged and lift the circuit
traces.

David

Mirek Chmiel wrote in message
news:3fb80cf5$0$9745$afc38c87@...
This TV is about 7 years old. About 2 years ago it had similar problem. At
that time, we had a local company fix it. On the bill, they stated
replacement of one transistor. Unfortunately, I don't have that info
anymore
to specify which one.
This time, I did google search on this problem and found much useful info.
The purpose for this email is to further pinpoint the root cause of my
problem.
For a couple of weeks, while TV was warming up, I did notice short picture
problems. For a fraction of a second the picture would be distorted.
Because
of a short duration, I couldn't tell exactly what the distortion was.
Yesterday my family told me, that there was a problem with TV. I couldn't
immediately check it out so can't say, if this was instantaneous or not.
When I finally looked at it, I saw a pincushion problem. Today I replaced
F902 fuse and for a short while, everything is OK. After few seconds
(10-20)
the red color fails and, on the convergence screen, it moves off half of
the
screen to the left. Blue is still pretty good. At this time, I can smell a
burning component and I turn the TV off. After checking for hot
components,
I did notice, that the top STK is hot.

At this time, I'll follow the advice from David Kuhajda from 2000/06/09
for
a Sony RPTV KP-41EXR96 :
If the fuse is blowing, even intermittently you need to Replace both STK
convergence output ic's, check all the low ohm resistors in the
convergence
output circuit. Then check the vertical output ic and the 2 small fusible
resistor to the vertical ic, typically when one of the convergence ic's
starts
to go it opens up the fuse, which unbalances the voltage to the vertical
ic,
if
it is not bad now, it will likely fail within the next month. I had 3 in
a
row
that got 2 convergence ic's and a fuse, only to have the vertical ic fail
within
a month later, so we now replace the vertical ic whenever either the +15v
or
-15v fuse opens up, order the ic by number from MCM or other generic parts
distributor, as well as the stk outputs, Sony wants way too much for these
high
volume parts, and they buy them from the other manufacture as well.
David

If anyone has any additional info/advice please let me know.

Thank you.

Mirek

You are still looking at the same voltages driving the convergence ic's.
Those should be replaced regardless. The vertical ic is not a concern if
you are not worried about the chance of having to open the set up again and
replace it later. It is not like you will have to make another trip out to
fix the set a second time.

Sony models use almost identical internal electronic chassis designs for any
given run. I would have to check but since your set does fall at the same
vintage, 7 years or so, as the other Sony chassis that had the same
problems, I would be suspect of the vertical output ic. To be sure is the
signal board with the fuses and vertical output ic mounted vertically on the
right side of the set (when looking from the rear) with the convergence
board mounted towards the front of the set?

David

Mirek Chmiel wrote in message
news:3fb82c40$0$9746$afc38c87@...
Thanks David.
Since you were dealing with different TV before (RPTV KP-41EXR96 ), does
the
rest of your advise apply to my model. At this time, I don't have a
schematic for this TV. So far I verified, that all low ohm resistors are
OK.
Should I replaced vertical ICs?

Mirek
"David" wrote in message
...
One special note. When you remove the old convergence ic's, completely
remove the old heatsink compound and reapply an air tight thin coating
of
heatsink compound to the new ic's. Make sure they are firmly attached
to
the heatsinks.

Be very careful not to damage or overheat the circuit boards when
removing
the old parts. Sony boards tend to be easily damaged and lift the
circuit
traces.

David

Mirek Chmiel wrote in message
news:3fb80cf5$0$9745$afc38c87@...
This TV is about 7 years old. About 2 years ago it had similar
problem.
At
that time, we had a local company fix it. On the bill, they stated
replacement of one transistor. Unfortunately, I don't have that info
anymore
to specify which one.
This time, I did google search on this problem and found much useful
info.
The purpose for this email is to further pinpoint the root cause of my
problem.
For a couple of weeks, while TV was warming up, I did notice short
picture
problems. For a fraction of a second the picture would be distorted.
Because
of a short duration, I couldn't tell exactly what the distortion was.
Yesterday my family told me, that there was a problem with TV. I
couldn't
immediately check it out so can't say, if this was instantaneous or
not.
When I finally looked at it, I saw a pincushion problem. Today I
replaced
F902 fuse and for a short while, everything is OK. After few seconds
(10-20)
the red color fails and, on the convergence screen, it moves off half
of
the
screen to the left. Blue is still pretty good. At this time, I can
smell
a
burning component and I turn the TV off. After checking for hot
components,
I did notice, that the top STK is hot.

At this time, I'll follow the advice from David Kuhajda from
2000/06/09
for
a Sony RPTV KP-41EXR96 :
If the fuse is blowing, even intermittently you need to Replace both
STK
convergence output ic's, check all the low ohm resistors in the
convergence
output circuit. Then check the vertical output ic and the 2 small
fusible
resistor to the vertical ic, typically when one of the convergence
ic's
starts
to go it opens up the fuse, which unbalances the voltage to the
vertical
ic,
if
it is not bad now, it will likely fail within the next month. I had 3
in
a
row
that got 2 convergence ic's and a fuse, only to have the vertical ic
fail
within
a month later, so we now replace the vertical ic whenever either the
+15v
or
-15v fuse opens up, order the ic by number from MCM or other generic
parts
distributor, as well as the stk outputs, Sony wants way too much for
these
high
volume parts, and they buy them from the other manufacture as well.
David

If anyone has any additional info/advice please let me know.

Thank you.

Mirek