Since the B+ for vertical deflection circuitry flyback derived and is
powered by the flyback it won't have the normal "drift over the
vertical scan" like in the power line derived B+... ...by the way, 100
mv ripple is terrific, only about 1%, so I don't think that is an
issue.... if you think it is, tag on an additional filter cap after the
series diode coming from the flyback.... say 470uf at 35 volts.... see
if that makes a change for the better.
Are you certain that the yoke is not defective.... did it ring test OK?
The LA7838 or NTE subs are fairly cheap, go ahead and replace so you
can confirm that the problem is not with the chip.... the NTE subs for
the Vert Delf chips have always works fine for me. The small cost for
the chip is a lot cheaper than many hours pulling out your hair.
Look for leaky diodes other than the zeners.
It is possible that one of the new replacement caps has marginal ESR...
I always check two or three of them in a package and select the very
best one for critical circuits. Not all new parts are always good.
electricitym
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