1) Replace all caps in power supply
2) Replace all CMOS chips (4000 and 14000 series) Especially the 4016 and any Analog Switches, they fail because of poor handling when installed. Insure all replacements are not rushed into the IC sockets as it is common for a Tech to discover a pin not seated properly.
Thanks. Sorry for the limited amount of info but I will add info along the way. Voltages are ok. I have not used the oscilloscope to see eventual fluctuations thou and a cap replacement is scheduled.
One thing I would like to understand is what could cause notes triggering. I mean: where do the "trigger note" inputs coming from the keyboard and midi in go? Which chip computes the keyboard matrix and midi in signal? Because i think I should start probing there...
Thanks!