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From: treesh@vangogh.helios.nd.edu
Newsgroups: comp.sys.cbm
Subject: Re: Yet an other C64 repair problem
Message-ID: <1990Nov26.132506.6411@news.nd.edu>
Date: 26 Nov 90 13:25:06 GMT
References: <1990Nov13.162259.981@vax5.cit.cornell.edu> <4125.27440883@cc.nu.oz.au> <1990Nov16.221620.10964@evax.arl.utexas.edu> <1990Nov17.213703.19417@DMI.USherb.CA> <10117@pogo.WV.TEK.COM>
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I have seen this problem before, although Im not sure exactaly what casues
it, I can safely say its proabaly not a digtal problem.  It looks like so
me kind of forign frequency is getting into the video output amp circuits.
Perpase a bad fitler cap in the internal power supply (not external power
pack).  If you have a variable DC regualted clean power souce, apply
+12 Vdc onto the power Vcc of the Vic chip and see if the problem clears
up.

ctfm