Troubleshooting a Kaypro II power supply

[hideehoo]

Picked this up from a neighbor awhile back, didn't power on at the time and the 12V line showed 0V under load, no load it showed almost 12V. Unplugged everything except for the logic and video boards, did a quick check on the boards and didn't find anything pulling the 12V line down, so just stuck it away and finally had a chance to tear into it again today. Interestingly it is now working, but showing about 4.5V on the 5V line, and 11.6 on the 12V line. -12V is slightly high at -12.3V. It's a Boschert XL60-3601R.





Everything looks in good shape, just a little toasty by a couple of resistors on the far side.




Some yellow Rifa filter caps to replace before the release the magic smoke, but I'm not quite sure where to start here. Any known/common failure points in these guys?

 

[kurt_kayger]

Hi
I'm looking for a wiring diagram for this power supply.

I have this power supply REV B in one of my Kapro's. Otherwise exactly as described.

Is there a wiring diagram anywhere?

greeting
Kurt

 

[kurt_kayger]

Hi,
I have removed or replaced the three 4700pF capacitors.
My Kaypro is working again.

greeting
Kurt

 

[acgs]

Glad it was just a "simple" replacing of the capacitors problem. Otherwise, it might have been one of those "can't figure out what's wrong" problems.

Luckily, you can always replace the whole power supply if you run out of other options.