How not to fix a classic mac (or: fried logic boards) - test-drb@ccmp.vtda.org

13 Nov 2007

...
  Date: Mon, 12 Nov 2007 22:45:09 -0800
 From: Josh Dersch <derschjo at msu.edu>
 Subject: How not to fix a classic mac (or: fried logic boards) 
...
  The other day I picked up a Macintosh 512k with a
broken monitor for $5
 thinking that it'd be a fun project to hack on (yes, another thing to
 add to my pile of things to hack on, just what I need :)).

 First point of business, I discharged the CRT.
 To the main chassis.  This, as I have now discovered, is not what you
 are supposed to do to discharge the CRT unless you want to destroy the
 logic board.

 Anyone out there experienced this failure mode?  Any
 obvious things to check? 
That particular failure is documented in Larry Pina's "Macintosh Repair
and Upgrade Secrets" and probably in "The Dead Mac Scrolls" as well. 
I'd
look it up for you, but I don't have my books with me here.  It's
definitely an IC, but I don't remember which one, nor how rare/common it
is.   If someone else doesn't jump in with the answer, email me (to remind
me when I'm at home) and I'll look it up.

Jeff Walther