Electrolytic Caps in CBM equipment

From: Rob Clarke <crock_at_clarke-family.org.uk>
Date: Sat, 08 Sep 2012 15:26:28 +0200
Message-ID: <504B4784.1090200@clarke-family.org.uk>
Good afternoon gentlemen,

The problems with aging electrolytic capacitors is well known but other 
than those found in the switching PSU's of European CBM-II machines, 
they've never caused me specific problems in the past.  I often replace 
them in PET monitors, but that's really out of defensiveness to make 
sure the picture is as good as I can get it.

That was until I received a Japanese VIC-1001 a few weeks back. Of the 7 
electrolytics on the board, at least three had failed to the point of 
preventing the machine working. The big 4700uf across the outputs of the 
rectifier had failed 'shorted' causing the fuse to blow, the 1uf cap 
used in the 555 1-shot circuit has also failed, so RESET never went high 
and finally one had failed in the video circuit so I got no picture.

These were all made by a company called Bellcon which I'd not come 
across before. Has anyone else had any other issues with consistently 
problematic caps in CBM equipment, either by manufacturer or in specific 

Pic of the failed ones: http://inchocks.co.uk/commodore/VIC/Bad1001Caps.jpg


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Received on 2012-09-08 14:00:05

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