yamaha rx-v2095 wont power on

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In this circuit, the relay R801 upon power on instantly shuts off the switch.

What could be at fault ?
Thanks.
Srinath.
 

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Hi,
It is possible that the main cpu IC3 it is detecting DC voltage from one of the 5 channels output when the relay RY801 it is enable and immediately disable the amplifier power on. At the top of the drawing for the CPU you can see the Protection signal and the DC detect coming to the CPU. With the voltmeter check pin 36 to see if a dc signal it is coming in. I think it should be zero.
 
ggrossklass: I will check that, but the transformer probably is fine.

Tauro221: How quickly will that DC detection happen. This shuts off instantly, you press the on switch and you hear 2 clicks ... It may have that DC detect code sitting in the buffer and instantly shut it down ...
I am working on resetting it, then I'll see if it does that.

Thanks.
Srinath.
 
I am unable to get it into diagnostic mode. It does not even power up for that.
As per manual if it power off within .5 seconds and display isn't provided, the abnormality may be in the power supply for the display.
OK I will find where that is and see if I can isolate and trouble shoot it.
Thanks.
Srinath.
 
Hi,
I do not think you can go to the diagnostic. The micro it is the one that power the main power. The micro has their own power supply feed by the T801. In other word it is powered all the time. I think it is protecting the speakers. See if you can read the voltage coming from the each of the five speakers output when you turn the switch on. Maybe you have enough time to read it. Any one with voltage will trip the relay.
 
And as I power it up, for a fraction it flashes to 7.6, or 9.6, or 12.5 or something ...
My guess it flashed to 0 for a micro second but I cant catch it ...

The left leg, not the one connected to ground (no idea what is what, that transistor is invisible without removing the board) - @ power up, it flashes 3v, 4v something.

Cool,
Srinath.
 
Last edited:
Hi,
Another thing has to do with the shutdown it is the PRV signal. It indicated that you have a problem with one of the power supplies. All power supplies voltages are tied to a point and the signal goes to the micro IC3. PRV it is pin 65 for the IC3 and it is located in page 68 to the right of the page. It should be + 5 volt = 1 to the micro processor.
 
That chip I am still looking for, where did it disappear.
Anyway on that main board I have what looks like a burnt q127.
Thanks so much tauro0221. You've helped me with other amps too in the past, like my HK 7000 and onkyo 805.
Thanks a million. I am a motorcycle hobby mechanic, if you were to have a motorcycle issue let me know, I'll see if I cant help you fix it the way you have helped me.

Cool.
Srinath.
 
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