Heathkit H89 Video Question

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sun Aug 31 17:44:00 2003

I have now dug out the H89 scehamtic. Well, it actually claims to be the
Zenith Z89/90 schemaitc. but AFAIK they're the same thing.

> > properly sized, and stable. After the unit operates for 10-15 minutes, the
> > video breaks down, first by jittering slightly for 30-60 seconds, then it
> > goes to a single vertical line on screen that fades to black. At this time,
> > the filament on the CRT also stops glowing. If I leave the unit off for
> > 20-30 minutes, it comes back with good video for a bit, then repeats the
> > above. If I turn the unit back on right away without a cool down, there's
> > no display/no filament glow.
Received on Sun Aug 31 2003 - 17:44:00 BST