I have a Yamaha Electone HS-6 dead. Checked the power side and found amplifier is ok and power to all boards and IC,s ok. Main MC and slave Mc,s are also getting 5V . Amp supply 24-0-24 is also OK. Other than that +15,0,-15V supply is also OK.. RHYTHM GENERATOR output side to mixing amp IC.s do talk to the speakers. Beyond that all is dead, but power to all IC's are OK up to keyboard scanners. I tried factory rest also but no success. Any helping advise will be appreciated. Thanks.