30 May
2004
30 May
'04
12:33 p.m.
I'd buckshot the components in the switch driver,
such as the IC. Sounds
In a supply of this age, I would not be suprised if the chopper driver
was discrete transsitors.
Anyway - I found the problem - It was a shorted capacitor on the primary side
Well done!
of the transformer - what threw me off was it was NOT
one of the electrolytics...
There's another one beside it which is just like it, so I think I will replace
both.
Maybe part of the snubber network on the primary of the chopper
transformer. In which case, check the associated diodes too.
Supply works fine now - and so does the entire machine.
(Joy at getting an old Apple clone working somewhat overshadowed by the fact
that I finally found a Kaypro today!)
I really must find a CP/M luggable sometime....
-tony