Re: [stella] Super Pong schematics?

Subject: Re: [stella] Super Pong schematics?
From: "Roger Williams" <mer02@xxxxxxxxxxxxx>
Date: Thu, 23 May 2002 18:34:10 -0700
From: Adam Thornton <adam@xxxxxxx>

> Well, bumping the supply voltage got rid of the problem, at least last
> night, and since I think I'm going to have to cut the heads off the
> screws to get into the case, I'm inclined to just leave it until it
> fails more authoritatively.

If bumping the PS did it you almost certainly have an electrolytic
capacitor failing.  (I doubt a home unit of that vintage would have
tantalum bypass caps, but if it does one of them could also be
the culprit.)  This would show up in troubleshooting as AC on
the "regulated" power.  Undervoltage of the digital portion of
the chip each cycle would cause it to lose its memory, while the
analog circuits (which use their own caps to store position info)
would tend not to be affected as much, or in the same way.

--Roger Williams

P.S. They make reverse drill bits which can be used with a
reversible drill to drill out those pesky oddball screws.  Or
you could use a Dremel tool to cut a regular slot...

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