I bought a second hand yamaha rx v1900 av amplifier and the right and left front channels are blown,4 power transistors 4 drivers 2 zener diodes and 2 protection resistors,i have replaced these components but still the amp will not stay switched on unless i use diagnostic mode,when in diagnostic mode i have found one of the power supplies are faulty which supplies the main amp pcb,the manual says there should be a +/- 61 volts but these are not correct so i disconnected them from the main amp board and the voltages were nearer those stated in the manual of +/- 61 volts,i have spent much time trying to find the fault on the main amp board but i cant find any problems,as an engineer im not use to repairing these modern diagnostic type amps and yamaha
are not helpful to me and just want me to send to a service centre and charge big money,the manual gives very little service information on the diagnostic codes for this amp(,i wonder is there anyone on this site would can advise me on repairing this amp).
are not helpful to me and just want me to send to a service centre and charge big money,the manual gives very little service information on the diagnostic codes for this amp(,i wonder is there anyone on this site would can advise me on repairing this amp).
