Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!ncrlnk!adds!tanya
From: tanya@adds.newyork.NCR.COM (Tanya Katz)
Newsgroups: comp.sys.att
Subject: RE: Screeching Noise & Screen Gibberish
Keywords: 3b1/7300 terminal gone crazy
Message-ID: <1244@adds.newyork.NCR.COM>
Date: 10 Nov 89 15:24:53 GMT
Organization: Applied Digital Data Systems Hauppauge, NY
Lines: 53


In article <12336@fluke.COM> Craig Johnson writes:

>What exactly was screeching?  This is terribly important to answering
>your question.  Possible sources are, the hard drive, the monitor, the
>power supply, and the speaker.  I'm going to guess it was the power
>supply.

Just to recap my opening remarks in <12324@adds.ncr.com>:
>>On Sunday Morning, about 7:30 am, just after my husband complained
>>that I left the computer on and it was "noisy,"  tfk, my home machine
>>must have taken offense to his remark, because it started to emit
>>a high pitched whine. 

As best I could determine, the screeching sounded like it was coming from
the terminal itself.  The unix-pc case was cool, especially around the disk
and fan areas.  The only keyboard response was to the first character
to turn on the screen display. I couldn't shutdown and nothing else was
being echoed by the driver.  The screen display looked like garbage.

>The scrambled display is indicative of a processor which has lost its
>mind (due usually to misread opcodes), or a video memory which has
>suffered a power hit.  In either case, a sagging Vcc (5 volt supply) on
>the motherboard will cause this kind of nonsense.  I'm suspicious that
>your power supply experienced a brownout, either because the AC main
>had a problem or because the power supply itself is failing.  Further, 

Brownout definitely crossed my mind.

>If it ran in this mode very long, its possible that the power supply
>overheated some of its components.  I would be suspect of its long term
>reliability.  Now would be a good time to get a spare power supply from
>Halted Specialties if you haven't already.  [thanks Thad, I've got mine]

Would you post or email me the address and/or phone number of this supplier?
 
>Well, I could be all wrong about your problem Tanya, but this is at
>least one good possibility.

Thanks for the input.  I am receptive to all possibilities.
I have booted the machine several times since last Sunday, and it
has been fine.  But I'm cautious...

-Tanya

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| Tanya Katz                  (516) 231-5400 x430 |
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