4 Jul
2000
4 Jul
'00
3:15 p.m.
Tony:
At 06:42 PM 7/4/00 +0100, you wrote:
Here's a wild guess that you might not have thought
of.
What about a fluctuating reference voltage to the RAMDAC? That would
affect all of R,G,B at the same time. If the reference is external to the
RAMDAC, maybe it's faulty. Or maybe there's a decoupling capacitor on the
reference line that's gone leaky and is pulling the line down.
Sounds like a good possibility. Yes, since the failure affects all
colors, it probably originates before any hold/buffer for each color,
and that means either the reference or the summing amp (I assume that
there is a summing amp? it would need to have a very high bandwidth,
though). I'll see if I can make out anything. By the way, today,
the symptoms were present for 5-6 hours and then they went away a few
minutes ago.
carlos.