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Subject: RE: Betr: Re: [Simmons Drums] SDS9 start up problems

From: Steve Ridley <spr@...>
Date: 2007-09-27

> have also checked the power supply and all is good there as
> well,

Do you have schematics? If none are available online, I
think I have some, but they may take afew days to find.

BTW, the PSU should give +5v, +15v and -6.5v.

> the only clue I have is that by removing the Eprom from inside
> on the board (SDS9 6.0)nothing happens at all at power on and
> reinserting takes the system back to the fault, could it be possible
> that this eprom has lost information from the lack of power over the
> period of time and is causing my errors?

The system EPROM tells the processor what to do. They don't
die very often and don't need power to retain their data.
If the EPROM was duff, the processor wouldn't even know about
the display, let alone be able to send a "6" to it. The six
might be an error code (anyone got full service notes?) or
a random symptom of the error, but it sounds to me like the
EPROM and processor are working and something else is
stopping them.


Steve