Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!husc6!bbn!rochester!cornell!batcomputer!braner
From: braner@batcomputer.tn.cornell.edu (braner)
Newsgroups: comp.sys.atari.st
Subject: Re: High pitched whine -- Definite ouch!
Summary: 1040s are fixable.  Monitors are worse.
Keywords: high resolution video
Message-ID: <4783@batcomputer.tn.cornell.edu>
Date: 12 May 88 18:00:09 GMT
References: <468@unh.UUCP>
Reply-To: braner@tcgould.tn.cornell.edu (braner)
Distribution: na
Organization: Cornell Theory Center, Cornell University, Ithaca NY
Lines: 23

[]

Over a year ago Atari informed its dealers on how to fix the problem
with whining 1040ST's.  It turns out that the culprit is the chip
that generates the +-12V for the RS232 stuff from the main +5V supply.
This chip oscillates, with the help of a capacitor, a resistor and a coil.
All three should be replaced with new components of different values.
I did it myself on my 1040 with success: complete disappearance of
the whine.  Ask your local Atari dealer for the info or a fix.
(By now I have a hard disk so my ST system is noisy again :-(  )

For all of you who suffer(ed) from that whine:  Some people (like me)
can hear the 15,750 Hz whine emitted by the ST _color_ monitor and all
other standard (lo-res) monitors and TV's.  It is a lot louder than
that 1040 whine.  It causes me physical pain.  Please be considerate
with your fellow people (and animals!) when using these archaic devices.

Anxiously awaiting a full transition to higher-resolution video in both
broadcasting and computing...

- Moshe Braner

(Still looking for a used 520ST system)