Darned capacitors again!


Craig Sawyers <c.sawyers@...>
 

This isn't directly related to Tek gear, but is another cautionary tale
about failing electrolytics.

Central heating has been pogressively unreliable at chateau Sawyers, until
eventually it wouldn't start at all (yesterday). Now I don't like fooling
with gas heating, simply because I'm not familiar enough with it and don't
have the necessary test gear to make sure I'm not going to gas the family.

So I called out the tech, and he said "it's the controller board". So to
cover the bases, I said to him to go out and get a new board and in the
meantime I'd try and fix the old one.

Well, 10 years old - and there was an open circuit capacitor! Dinky little
22uF 63V Philips axial lead beastie. Replaced that, and as a precautionary
measure the other two electrolytics on the board, although they measured OK.
Problem fixed.

So I guess that electrolytic failure isn't restricted to the old gear. In
the past couple of months, to add to the central heating one, I have had 3
shorted tanatalums (in a Tek 620 monitor) and open circuit twistlocks in a
Tek Type 111, a GR 1216A and a GR 1263B.

Craig

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