[sdiy] PPG Wave 2.3 Boot Problem

Synthusiast synthusiast at gmx.net
Thu Jun 20 02:31:25 CEST 2002


I'm in the process of repairing a non-functional PPG Wave 2.3. The problem
is, that the PPG refuses to boot. When powered up, the backlight of the
display goes on, and the top line of the display shows a long black bar and
that's it. The unit is in good shape, the only thing is, that the machine
doesn't have a battery installed on the I/O board. As the battery is used
for keeping patches and sequences in memory, the missing battery shouldn't
affect the booting sequence IMO. I've done several tests on the unit
(checking voltages, reseating IC's, watching MCU pins on o-scope, etc.) and
came to the conclusion that either the MCU has died or that the EPROM code
is messed up. I'm thinking it's the EPROMs, but until I've made myself an
EPROM reader, did anyone of you have a similar experience with your PPG and
if so, what did you do to fix the problem?


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