Disklavier

1995 Mark100 power supply component quit & looking for fix.
Sent it to TAP electronics in California. Tech said Yamaha in Japan working on solution, but added that the unit is a paperweight. Any advice or hope?

The new power supply unit and replacement ICs are no longer available in also Japan.

I have power unit but it’s repaired power unit.
But these are Japanese version.
If you install Japanese version,then you need to change the safety parts in attached photo.However ,please do everything at your own risk.
(S1--S21)


The typical cause of failure is the power supply. 
 How to check for Power unit by stand alone.(without Disklavier)  
 The power supply startup routine is as follows and please see the attached Photo.   
 1:Main power switch on AC INPUT  
2:Controller Power switch on(connect sw+ and  sw- )   
3: Relay 1 on.  
4:+8V and +20V system voltage are out putted.    
 5:Pon+ is returned from the piano.(connect  Pon+  to GND)  
 6:Drive relay 2 on.  
7:HV(drive high voltage) is out putted.      

If you get high voltage  few minutes by your power supply. The power supply is good. 
And if the power supply is good then I guess pedal or key drive  thermo or control board is dead.   

 A typical power supply unit  fault is a defective capacitors. 
 Ex:c12,c15,c22. Increase voltage proof and replace these and other capacitor,and fix pattern..