Hi;

I'v posted this before. You top techs out there have a chance to one-up
me. I'm not even looking for a symcure here, just advice on where to
look. Somebody helps me nail this one, not only do I owe you a favor,
I'll actually _humble_ myself. That is a rare enough occasion to be
priceless, but I am at a dead end.

The set blanks the video every eight seconds then fades back. Heat does
not affect it at all. I have scoped the ABL line and everything to the
jungle IC and nothing is changing at this rate. The ABL climbs just a
hair when it blanks, but if it were the cause it would be dropping. All
Vccs and inputs are normal.

I have already changed the jungle as well as the micro and it looks as
if the EPROM has already been changed.

If you turn the contrast all the way down and bring up enough
brightness to see something it does not happen. Something is resetting
the control to zero and it's coming back gradually. Sync is not
affected, but I already knew the Y input to the jungle wasn't it.

I have a close enough print, I have a scope and know how to use it, to
be at a dead end is unacceptable.

Let me ask this, possibly someone knows more about just how the data
are sturctured; Can I somehow stop the data from reaching the jungle IC
and have the set still run ? Seems like you would lose control of
everything but the symptom may stay or go. I can probably get the
details on every chip in there as to whether it's a pullup output or
whatever for the clock and data, but not the micro. If you know what
that costs you know why I really don't want to fry it. If you interrupt
the line, I figure the data has already loaded and the chip should
continue to operate. I wouldn't have to mess with the clock line (I
think). If it is feasible to run this test it would prove that it's a
data problem, such as the jungle IC getting reset when a certain pulse
train comes along. Even this is far fetched, but like I said I am at a
dead end.

I usually like a challenge, and I'm the third tech to work on this. I
have confidence in the others' confidence, I know them. They are good,
and nobody butchered anything. They don't work with me now, but one of
them just did happen by today and he's pretty out of ideas too.

This is another one of those cases wher we will end up changing a part
that probably costs less than fifteen cents and it's kinda got me up a
wall. I walked into the bosses office making the "hair pulling out"
motion.

Thanks in advance.

JURB