30 May
2004
30 May
'04
9:13 p.m.
speaking of kaypros I may have a couple available shortly, they are in my
garage and I need to see which ones work and are complete I'm probably
keeping one of them.
At 05:33 PM 5/30/2004, you wrote:
What, not even a TL431 in the secondary-side regulator? That does suprise me.
>>
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.
It is - the only IC is the Opto-isolator.
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