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From: kenh@pogo.WV.TEK.COM (Ken Hillen)
Newsgroups: comp.sys.mac.hardware
Subject: MacPlus Analog Board Schematic Wanted
Message-ID: <8582@pogo.WV.TEK.COM>
Date: 20 Feb 90 16:39:39 GMT
Distribution: usa
Organization: Tektronix Inc., Beaverton, Or.
Lines: 12

The +5 volt power supply on my old MacPlus is starting to act funny.  If I
adjust it above ~4.8V the screen blanks and the speaker goes tick-tick-tick.
If I adjust it below ~4.6V the reset generator starts resetting continously
so the speaker goes ding-ding-ding.  When I set the voltage to ~4.7V the Mac
will usually boot OK, but due to what appears to be poor regulation it will
occasionally start resetting (ding-ding-ding...) or going overvoltage (tick-
tick-tick...).  I would like to get a schematic of this board if anyone has
one so I can attempt repairs.  Alternately, does anyone have any suggestions
for fixing this problem?

Ken Hillen
kenh@pogo.wv.tek.com