I helped a friend fix his Xa. We found a bad 2114 RAM chip, and
also a chip on the lower board that was shorting one of the data bus pins
to gnd, and bringing the whole system down. We had to cut traces to
isolate which chip it was, since that one bit went to a number of
chips, and none of them were socketed, and also the cable between
the bds was soldered at both ends. Hate doing that, but we did it
discretely and got things going again.
Bob
From:
"synthparts@... [oberheim]" <oberheim@yahoogroups.com>
To:
oberheim@yahoogroups.com
Sent:
Friday, October 3, 2014 1:07 AM
Subject:
Re: [oberheim] OB-Xa LED error code at boot time
The OB-Xa doesn't have any error reporting ability other than blinking the voices which can't tune during the auto-tune routine. Possibly bad CMOS, ROMs, RAM, or Z80. I've seen failures in all of those on Xas.
Doug
synthparts.com