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From: ralph@mit-atrp.UUCP (Amiga-Man)
Newsgroups: net.micro.amiga
Subject: Re: Noisy amiga monitor
Message-ID: <282@mit-amt.MIT.EDU>
Date: Thu, 7-Aug-86 11:07:15 EDT
Article-I.D.: mit-amt.282
Posted: Thu Aug  7 11:07:15 1986
Date-Received: Sat, 9-Aug-86 08:29:38 EDT
References: <1055@jade.BERKELEY.EDU>
Sender: usenet@mit-amt.MIT.EDU
Reply-To: ralph@mit-atrp.UUCP (Amiga-Man)
Organization: MIT Cognitive Information Processing Group (CIPG)
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In article <1055@jade.BERKELEY.EDU> mkent@violet.berkeley.edu () writes:
>My amiga monitor has started producing a high-pitched sound after it warms
>up.  This is extremely annoying, to say the least.  I've discovered that
>the old-style TV remedy (hitting the cabinet a sharp blow to the side!)
>works briefly, but the shriek returns.  Has anyone had a similar problem
>with a monitor?  Suggestions (non- Rube Goldberg) for its correction?
>          
Such noises may be due to the stepup tranformer which creates the high voltages
for the front of the screen. If they aren't mounted correctly or aren't wound
right you get noise. There's also the deflection coils which might make such
a noise. You hear a high pitched whine cause the horizontal sweep freq.
is around 15Khz, just at the top of human hearing range.

I really wouldn't recommend hitting the thing. It will just loosen up
circuitry inside, especially the picture tube guts, making failure happen
sooner. Perhaps you could get it serviced, or if you know what you are
doing (LOOK OUT for stored high voltages, even when it's OFF!) you
could investigate the noise source.