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From: cdold@starfish.Convergent.COM (Clarence Dold)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Computer Whine
Message-ID: <727@starfish.Convergent.COM>
Date: 22 Sep 88 19:32:17 GMT
References: <6319@xanth.cs.odu.edu>
Organization: Convergent Technologies, San Jose, CA
Lines: 19

From article <6319@xanth.cs.odu.edu>, by rlb@xanth.cs.odu.edu (Robert Lee Bailey):
> In article <45900151@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes:
>>
>>I just moved my PS/2 model 80 from my very noisy lab to my nice 
>>quiet office. I now notice a very odd thing: When idling at the DOS
>>prompt the system box makes a loud, high pitched whine. When it
Another possibility is the CPU heatsink!
On the Intel 80186 and 80286 ( not sure about 386 ), the flat-pack CPU
is held down by a flat piece of metal and a spring.  This piece of metal
can oscillate, and it seems to be associated with activity on the board.
... I've got my flame proof 'theory' suit on ...
It really does happen.
Try popping the heatsink loose, and snapping it back on.
This was a prevalent, although low noise, problem on a multi-processor
system that I saw several renditions of, also using a switching supply.
-- 
Clarence A Dold - cdold@starfish.Convergent.COM		(408) 435-5274
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