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From: gnome@oliveb.UUCP
Newsgroups: comp.sys.mac
Subject: Re: Is my mac about to fry?
Message-ID: <1419@oliveb.UUCP>
Date: Tue, 16-Jun-87 18:16:08 EDT
Article-I.D.: oliveb.1419
Posted: Tue Jun 16 18:16:08 1987
Date-Received: Thu, 18-Jun-87 04:09:35 EDT
References: <403@oswego.UUCP>
Distribution: na
Organization: Olivetti ATC; Cupertino, Ca
Lines: 25

in article <403@oswego.UUCP>, ostroff@oswego.UUCP (Boyd Ostroff ) says:
> 
> I use a Mac 512Ke with Apple HD20 at home and with the recent warm weather
> it has developed a high-frequency (15-20 khz) "whine" after it has been
> on for awhile.  It only seems to happen on warm (over 75 degree) days
> after the computer has heated up.

Well, it would be nice if you could narrow it down to either the analog
board or the HDU.  If it is the HDU, it's probably the infamous "squealing
grounding button" effect that causes the hard drive to squeal constantly
until someome goes crazy and disables it with a hammer.
Generally the grounding button, which resides at the center of the HDU
platter motor, isn't really needed and can be removed.

If it's your power supply, well, I'd recommend putting a fan on your
machine and, if you have access to someone, get a hardware person to
"reseat" the DC power cable connectors and test/tweek the supply voltage
to make sure it's within range.

Good luck,
Gary


"Unhappy MacNam..."
			-Bozos