Article View: comp.sys.mac
Article #9228Got them mean old power supply blues
From: kevin lund
Date: Sat, 09 Dec 1989 23:42
Date: Sat, 09 Dec 1989 23:42
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1336 bytes
I have a really ancient mac (originally 128K) and, over the years, the
analog board has required no more than an occasional resolderning. Until
now...
The symptoms are: no video (not so much as a measly dot in the middle),
sound is corrupted (a buzz instead of a bong when it comes on, and when
reset...so I guess it's supplying power ok), and not much else (won't boot).
There is a big fat transistor (Q3 I believe; it's at the top and has a big
heat sink on it) which gets extremely hot and, with the power off, has no
appreciable resistance though any pairs of it's legs (bad sign if I don't
miss by guess).
So, does anybody have any idea what the problem is? I could always
try replacing the transistor but maybe it was wrecked by something
else...is all else fails, where can I get a new board, cheap?
thanks
kevin kevin@ucrmath.ucr.edu
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!helios.ee.lbl.gov!ucsd!ucrmath!kevinShow Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!helios.ee.lbl.gov!ucsd!ucrmath!kevin From: kevin@ucrmath.UCR.EDU (kevin lund) Newsgroups: comp.sys.mac,comp.sys.mac.hardware Subject: Got them mean old power supply blues Message-ID: <2995@ucrmath.UCR.EDU> Date: 9 Dec 89 23:42:48 GMT Reply-To: kevin@ucrmath.UCR.EDU () Distribution: na Organization: University of California, Riverside Lines: 18