pss580 suddenly no power although all connections and transformer fine - also have lost the operating instruction book - is this available on line ?
Try a different power supply, does it work off batteries?
Make absolutely sure that the power socket is still working by testing the voltage further into the circuit. Check the switching on the socket still works,
Check the power switch
Check the output of any voltage regulators
Check you are getting around 5v on the power pins of any logic chips
Any Yamaha manual ever produced can be found at http://www.yamaha.co.jp/manual/english/ (http://www.yamaha.co.jp/manual/english/)
I agree to check the voltage regulators input and outputs (or just outputs!), and any +5V logic raills...
I am having a heck of a time with my Korg Poly 800 an dits supply +5V rail!
Good luck, let us know how you get on...
Cheers,
Nate