Ditto Sofie's comments. Also, clean any electrolyte from the board and
resolder all connections in the circuit. The 200v cap may have a high ESR
and may also cause problems. Use the original value electrolytics.

Leonard

"Sofie" wrote in message
...
Gene:
Replace (remove the old caps, don't shunt them) the remainder of the C3xx
caps in and around the vertical output chip and look especially for C301,
it
is hiding about 2 inches away from the rest of the C3xx caps and is toward
the center of the board near a large chip (jungle IC)..... and definitely
replace it.... usually 1uf @ 50V .....
Most of the electrolytic caps, with age and heat will suffer from high
ESR,
degraded capacity, leak corrosive electrolyte and many times will become
electrically leaky or even short...... because of this you need to
actually
remove the caps, don't shunt them. Unless you have an ESR meter to
properly test them, just replace them all, there are only about 6 to 8
units
so it is fairly easy and cheap.
When replacing the electrolytics be certain to observe polarity.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
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"Gene Gardner" wrote in message
...


I inherited a Toshiba model CF2750K, chassis# TAC 9011, with the
notorious
vertical
problem...compressed to center and upper half...bottom half dark. After
reading some
of the posted hints, I arbitrarily replaced the 1uf-50v capcitor in the
verical section.
It seemed to be the only 1uf in the vertical section, but it was C-305
rather than
the C-301 or C-342 mentioned by others. One mentioned that the quality
of
the capacitor
was important, so I replaced it with a paper-tubular (mylar?) 1uf-200v.
But apparently,
the set may have had two defects, because when I turned it on, it now
had
no vertical
deflection at all (bright horizontal white line in middle). I believe
the
handling of
the PC-board had caused a lingering problem to appear. I arbitarily
re-soldered the
seven in-line pins on IC-301 which I believe is probably the Vertical
power IC. It
had a large heat-sink.
The set now worked about normally, except that the vertical linearity
was a little
disappointing...a slight widening of spacing progressing from bottom
toward top, with
and exaggerated widening on the top inch of the screen. I could only
find
one pot named
vertical height, but could find nothing for vertical linearity. There
were
other
un-named pots in another section but did not to turn them, and they were
sealed. They
did not have the expected 300 series number.
I did shunt an extra 660uf across an existing 2200uf (300 series) and
shunted an
extra 25uf across an existing 10uf (300 series)...both in the vertical
section.
Adding these made no significant improvement. Incidentally, capacitors
of
about 3/8"
diameter can be tack-soldered on the bottom side (just enough space)
without removing
the original (electrolytics almost never short).
Does anyone have any hints as to improving the vertical linearity on
this model?Is it
possible that the high quality of my 1uf capacitor was TOO high? (one
poster suggested
that the circuit was very critical to the quality of the 1uf capacitor)