Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!web-2c.berkeley.edu!c60c-1ea
From: c60c-1ea@web-2c.berkeley.edu (Yen Yuanchi Hsieh)
Newsgroups: comp.sys.amiga.tech
Subject: Grounding problem??
Summary: Machine flakey -- shield ground has voltage waveform
Keywords: Shield Ground, flakey 500, HELP
Message-ID: <23582@agate.BERKELEY.EDU>
Date: 25 Apr 89 20:44:33 GMT
References: <358@nadia.UUCP> <21526@santra.UUCP>
Sender: usenet@agate.BERKELEY.EDU
Organization: University of California, Berkeley
Lines: 20

Hi all you netters -- got a question for y'all,

My machine has been acting VERY flakey recently, this include symptoms
like; external disk spins, but cannot validate disk; printer is missing
certain bits when transmitting (are = ara); external memory does not work,
or worse -- machine refuses to boot (green, purple, yellow, red, black +
static screens -- sometimes some random noise, drive clicking -- very
interesting really).

I noticed that the ground shield on the A500's supply was ~2 Volts at a
real high frequency waveform.  Is this normal -- is this normal ground
signal from the outlet -- all of the other outputs were nice and steady.
Could this be causing the problems?  (I've switched my 8520's -- exact
same problem with printer)


Help, please.  I'm getting tired of calling people, and sending it down to
get serviced, etc.

					-Dave