"T o d d P a t t i s t" wrote in message
...
I'm at the end of a long repair of this Mitsubishi CS-3535R.
I've replaced the switching regulator and related caps to
get the primary side working, the 30 volt regulator
transistor and related zener with bias resistors that burned
up, a burned zener and bad cap near the "black level
corrector IC," a couple of fuses and finally the vertical
output IC - a Sanyo LA-7838 and all the caps in the vertical
section.

The initial failure involved smoke and the repair was a
pain, as I smoked several components on the main board and
saw smoke once in the vicinity of the CRT neck. The last
bit of repair was the replacement of the LA-7838, which I
replaced with an NTE sub.

The picture currently has a slightly brighter horizontal bar
about 20% down from the top. The scan lines are slightly
closer together there, and I suspect that it is the closer
scan lines that make it appear brighter there, but it may
actually be brighter. The picture is slightly compressed at
the line, but looks OK above and below. The caps were all
replaced in the vertical section hoping to get rid of the
vertical problem (which was not there prior to the power
supply problems.)

I've gotten advice from some here whose advice I really
respect, and the consensus is that it's probably not the
vertical IC, despite the fact that I used a sub. However,
having replaced all the electrolytic caps in the vertical
section, I'm not sure where to go now.

I'm going to put a scope on the output, and I expect I'll
see a kink in the ramp at the 20% point. I thought I'd
scope the power to the vertical IC too, just to see if it's
fluctuating, but it goes through a pair of zeners and a
large cap, and the voltages look OK on the DMM.

Anyone want to give some more advice?
Thanks.

The natural function of the wing is to soar upwards and carry that which
is heavy up to the place where dwells the race of gods. More than any
other thing that pertains to the body it partakes of the nature of the
divine.

Plato, 'Phaedrus.'

Sounds like you either missed the vertical boost cap, usually about 100uF at
35V, near the vertical output IC, or else a B+ filter near the flyback,
something like 4.7uF at 160V or 10uF at 160V, etc. If it's the boost cap,
the vertical output IC will be running hot.

Mark Z.