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Re: Power supply repair
Wayne Stewart wrote:
I acquired a non functioning IIe power supply with some stuff. On
opening it up I found two diodes that were swollen and split. I used
parts from a clone power supply that had every cap leaking as
replacements.
I have no knowledge of the history of this power supply and I�m
wondering if something on the outside might have drawn too much power
or is it something on the inside that may cause it to fry those parts
again.
While I was looking at power supplies I decided to pop the cover off
an old Apple power supply I happened to find inside a clone. Found the
Apple logo on the circuitboard and all the parts are dated 1978.
If one line diode shorts, the other(s) short almost immediately, and
the line supply filter electrolytics will also be taken out.
If a line supply electrolytic fails shorted, the diodes will be gone
within seconds.
So it's hard to know exactly which scenario caused the failures, but
typically several components in the line supply will be zapped at the
same time. Usually, this also takes out the fuse.
-michael
NadaNet 3.1 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."