Thread: Zx81
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Old 28th Apr 2020, 9:18 pm   #289
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 9,218
Default Re: Zx81

Originally Posted by Slothie View Post
if you have replaced or tested the power supply electrolytics and any on the board?
The power supply on these is remarkably uncomplicated - just a 7805, and the only associated electrolytic is a relatively small one on the input - could be worth changing though. On the regulated side it's all ceramics.

The only other electrolytic I see is a 1uF on pin 26 of the Z80 which the originator of the drawing has neglected to mark, but it is the _RESET pin of the Z80 so that's the reset capacitor, obviously.

I'm afraid there are disappointingly few electrolytics for recappers to go at on these. The PSUs do have a bigger electrolytic in them and that will have been roasted by the heat from the transformer but John has two power supplies which I think power his other ZX81 OK.
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