24 Jun
2001
24 Jun
'01
1:06 p.m.
Hmmm... I have a major objection to 'whacking'
anything near a CRT....
Not only the risk of CRT inmplosion, but even if you
don't crack the CRT
you can certainly knock the electrodes out of
alignment.
tweak the adjustments. My guess is that this did once
have enough
height, and the reason the height has decreased is
due to component failure.
Look for dried-up electrolytic capacitors round the
vertical deflection
circuit. If it uses the well-known TDA1170 chip, then
there are a couple
of capacitors hooked up to that chip that can cause
this problem.
Be careful cutting the stuff off near the yoke (or
other wirewound
components) -- it's easy to damage the insulation.
I
normally cut it away
roughly in the centre of the blob (to free the yoke),
then remove the
yoke completely, then peel off the remains of the
gunge from the yoke and
the CRT flare. On the other hand, you shouldn't
need
to reposition the
yoke. this monitor worked once, with the yoke in that
position. The yoke
hasn't moved, so the fault must be due to other
failures.