Yamaha RX-V3800 - What am I missing?

[tojoko]

Hi
I would check on the powersupply pcb's, usually easy to take out in a Yamaha RX-V amp, I worked on a RX-V2500 that became hot and had a 100 hz hum in the speakers, it turned out to be bad soldering connections, visible as a extra ring around a component leg, found a few of them, resoldered them and it cured the hum, and heat problem.
Cheers, Tojoko.

 

[kapitiaudio]

no power RX-V Yamaha

Hi
For the guys that use an older type RX-V Yamaha Receiver, when it does not power on, very often the small Capacitor on the powersupply board is broken, the value way lower than the specified 22 nF, replace it with a high quality cap, it is, on most boards the C4 cap.
Cheers, Tom.

Just to clarify, you must replace it with a capacitor of the same type (polyester I believe). If you use a different kind of HV capacitor of the same value, the circuit will fail to work! This is a geek designed circuit, overly complex and unreliable.

 

[kapitiaudio]

HELP.
Read a thread...

My Yamaha RX V 1900 transformer really hot, is almost at the 5 second rule with the amps power in up the center and surrounds only.
WTF.
Thanks
Paul

You need to determine if it's the transformer itself or something loading it down.

 

[tojoko]

Just to clarify, you must replace it with a capacitor of the same type (polyester I believe). If you use a different kind of HV capacitor of the same value, the circuit will fail to work! This is a geek designed circuit, overly complex and unreliable.

Yamaha service stated a 22 or 33nF mkp or fkp 300 volt, I used Wima, will work, mine is running fine for years now
Cheers, Tojoko.

 

[tojoko]

Here is a pic of a powerpcb before repair....arrow points at broken capacitor, should be 22 nF measured just 7 nF.