31 May
2002
31 May
'02
6:03 a.m.
Another problem to keep an eye out for are tantalums that were inserted
onto the board *backwards*, with the polarities wrong.
I saw this on a few different production boards from different
manufacturers. It seems the power supplies work perfectly fine for a while,
and short out later on in life.
Replacing the capacitor fixed the problems.
- Matt
At 06:32 PM 5/31/2002 +0100, you wrote:
Tom Uban wrote:
Matthew Sell
Programmer
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I guess I will just proceed with repairing the
board. The 24v input seems
to be shorted to ground -- that shouldn't be to difficult to find.
Just a suggestion: I fixed an HP 1980B oscilloscope that had a shorted
power supply by replacing a shorted tantalum capacitor. Tantalums
tend to go short-circuit for no good reason, and result in the
short-to-ground symptom that you mention.
--
John Honniball
coredump(a)gifford.co.uk