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From: ash@hpindda.cup.hp.com (Art Harkin)
Newsgroups: comp.sys.mac.hardware
Subject: Mac Analog Board Problem???
Message-ID: <45160001@hpindda.cup.hp.com>
Date: 24 Jun 91 22:07:19 GMT
Organization: HP Information Networks, Cupertino, CA
Lines: 26


My MacPlus (upgraded from a Mac 512K) seems to be having
power supply problems. My screen brightness controller has to
be set to its lowest setting to make the screen be at its
correct brightness (otherwise, its too bright).
Also, I was having modem problems (one of them my have burned
out) and it may because of too high of a voltage being sent
over the RS232?  The modems work okay with another Mac.

I tried to get readings off the power supply to see if
its providing to much 5V or 12V, but it didn't seem so.
But, I do not have a schematic or checkpoints to totally
verify this.

Is this a common problem in older macs?
Is it fixable, the voltage adjustment knob did not seem
to help too much.

Is it possible to get an analog board for a Mac Plus
at a reasonable cost anywhere (in south SF bay area)?

Thanks in advance,   (replying by email will be fine)

Art Harkin

ash@cup.hp.com