On Monday 15 October 2001 10:18 am, you wrote:
> Suzanne,
> Sorry to hear that. A volt tester would be worth
> a try. Would love to see you stay, but if not
> I would take the group just to keep it alive.
> Bet you could get another broken one to use as parts
> to fix yours.
At first I suspected the PSU, the display appeared devoid of anything, and
the transformer was 'hot', even though it had been unplugged for a couple of
hours. But, my multimeter (and a dark room) confirmed that the PSU is fine,
the display lights up vaguely at each side of the display, but doesn't start
the init tests. It appears that there has been a 'death in the digital
domain' (to paraphrase black sabbath :).
When I have more time, I'll take my o'scope to some of the signal lines on
the CPU and such (look for clocks, activity on the address bus, etc), Mr
Walsh stated, in private email, that he has had to replace the CPU in the
past, with luck, its as simple as that - but there are a lot of other chips
in there that may not be replacable these days. Unfortunately, I suspect its
one of those diagnosises that is really going to require a schematic and a
lot of time, and a level of investment that I'm not sure I'm willing to sink
into it right now - While I loved my SD1, it was mostly being used as a
master controller, and I can envision 'diagnosis and repair' rapidly costing
more than just buying a new master controller.
Also as an electronics hobbyist, I can use this as an excuse to put time into
the '88key keyboard with poly aftertouch (thanks 3M for giving the world
'velostat') design' I've been (vaguely) working on.
