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Subject: Re: Fried Poly

From: Lee Mulvogue <lmulvogue@...>
Date: 2001-10-31

> >IIRC, when I looked at my original fried poly, the service manual said
> > >that D1 was the main protection circuit - but of course there was no >D1,
> >so...??
>
> Not that I know anything about the internals of the Poly but I would guess
> that removing D1 has something to do with transferring power to the RAM chip
> from adapter power to backup battery power.

I went back and checked, and it turns out the protection diode is actually D2. Hmm,
think I might have a look in my current poly to see if D2 exists in this one...

I've uploaded a text descriptor of each circuit section of the schematics - it's a
graphics-to-text conversion of a scan I did of the text in the service manual (which
I no longer have), so there may be a couple of glitches in the conversion, but I
think most of it was right, and I manually fixed any bits the converter couldn't
read.
A hell of a lot smaller to download (also a lot easier to read) than the original
jpg of the text... if only we could do that with circuits, too!

PS. Olaf, I like the idea of the panel-mounted sequencer and program write switches
- saves having to fumble around the back trying to figure out which switches are
which! Could also wire up some LEDs that come on when write is enabled... ooh, blue
ones, now that would be cool...! ; )
PPS. Your wiring efforts are a hell of a lot neater than mine. ; p