Vintage Synth Repair

Sorry guys as this is not vintage but I need all help I could get!


This controller seems to be sending MIDI messages by itself at random or intermittently after some time. Also the ‘Arperggiator’ LED lights and then all seems to go out of control. I’m not sure if it’s the Main CPU Board or the Top Right Board (where all the controls are) that is at fault. Hooking just the Main CPU Board through USB-MIDI I wasn’t convinced if the MIDI messages were generated either because it’s at fault or because its not connected to the Top Right (controls) Board.


Anyone has met with such a symptom?


I also would like to know if there’s a ‘Test Mode’ built in as in the manual I have nothing’s mentioned.


thanks,
cosmo