Path: utzoo!attcan!uunet!eplrx7!udel!rochester!rutgers!att!ihlpe!stuart
From: stuart@ihlpe.ATT.COM (S. D. Ericson)
Newsgroups: sci.electronics
Subject: Mac II Monitor Problem
Summary: Mac II Monitor problems
Message-ID: <3825@ihlpe.ATT.COM>
Date: 23 Nov 88 14:16:22 GMT
Organization: The Sage Hovel, Wheaton, IL
Lines: 32

My Mac II monitor started acting very strangely lately.  After
being turned on a few minutes, the monitor will "snap" periodically,
about every minute or so.  The "snapping" causes the screen to
jump and sometimes even go completely blank, necessitating
a reboot of the machine to get the display back.  

Being curious, I took the case off the monitor, disconnected it from
the Mac and plugged it in stand-alone.  The snapping persisted.
It seems to slowly build up a large amount of voltage and then
discharge it.  The sparking can be seen very plainly in the tube,
but I'm not sure it that is where the sparking is taking place, or
if that's jjust an electrical reaction of the tube to an outside
voltage arc.

This seems to be a problem in the high-voltage circuitry, so it's
not so much a Mac problem as a TV tube type problem.  (It arcs
when NOT connected to the mac.)   Anyone have any ideas as to what
may be causing this?  Any TV technicians on the net?  I'd hate
to have to go to Apple's "board-swap-fix" prices for a loose
connector or something...

Thanks in advance...

Stu



-- 
Stuart Ericson			AT&T Bell Laboratories
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