yamaha rx v-797

[Carlosraj]

Hi,

I am currently working on this amp. The problem is that the amp is totally dead (no power). It has two power switches, one is a master switch and the other is a main zone switch. Both switches have no response at all. Does anyone has a schematic for this amp. Pls assist.

Carlos

 

[cliffforrest]

I don't know why people find searching so difficult! 😀

Enter

yamaha rx v-797 schematic

into your search engine and you will find lots of info.

 

[sgrossklass]

Looking for the correct model might also help - there's an RX-797 (stereo unit), but no RX-V of said number.

Sounds like classic Yamaha standby power supply failure. Renew C254, check R261, and chances are you'll be back in business. I am guessing that mains surges do these no good. Sometimes people also find other faults like the odd dead optocoupler, but C254 really is the most common one. If you insist on measuring in the standby PSU, use an isolation xmfr.

 

[billiet]

My RX-797 had similar symptoms. This morning I replaced C254 as sgrossklass suggested and everything is working a treat!

 

[Carlosraj]

Looking for the correct model might also help - there's an RX-797 (stereo unit), but no RX-V of said number.

Sounds like classic Yamaha standby power supply failure. Renew C254, check R261, and chances are you'll be back in business. I am guessing that mains surges do these no good. Sometimes people also find other faults like the odd dead optocoupler, but C254 really is the most common one. If you insist on measuring in the standby PSU, use an isolation xmfr.

Thanks sgrossklass, you were right. It was C254. I replaced it and the amp is back to normal. Thanks to billiet as well

Carlos

 

[lwphilosopher]

Thanks sgrossklass, you were right. It was C254. I replaced it and the amp is back to normal. Thanks to billiet as well

Carlos

Hi, I am trying to find the C254 mentioned, however I just found one that says CB254 is it the same?

 

[lwphilosopher]

Looking for the correct model might also help - there's an RX-797 (stereo unit), but no RX-V of said number.

Sounds like classic Yamaha standby power supply failure. Renew C254, check R261, and chances are you'll be back in business. I am guessing that mains surges do these no good. Sometimes people also find other faults like the odd dead optocoupler, but C254 really is the most common one. If you insist on measuring in the standby PSU, use an isolation xmfr.

Hi, I just tested C254 and it has almost the specified capacitance by the manufacturer. Should I replace it anyway?