yamaha rx-v471 reciever won't power up.

[pawill]

I have a Yamaha rx-v471 reciever that won't power up. Nothing happens when I press the power button. I have the 5 volts and the 3.3 volts on the power supply board. I can't find a service manual or find out how to put in diagnostic mode. Any help would be appreciated.

[BennVenn]

Looking at the model on google images I had a similar model with the same fault about 3 yrs ago. There is a system reset IC that monitors the main system voltages. All measured correct however the IC was still triggering shutdown. From memory there was a cap attached which delayed the shutdown long enough for the supply to come up to voltage. This cap went bad and replacement fixed the issue.

Initially it would turn itself off when it heated up, then it would do it when cold, then it just wouldnt turn on. If your symptoms are similar, try looking at that.

[mzacharias]

Starting Self-Diagnostic Function: While pressing the “TONE CONTROL” and “INFO” keys, press the "POWER" key to turn on the power.
You may see a diagnostic screen appear, perhaps only briefly. Be prepared to write this information down and post back.