Hi! I need help! So I have a faulty amp Yamaha RX-V563. After three seconds it turns off. First I checked all capacitor visually and pcbs has no traces of burning. Then I disassemble amplifier and I'm just going down to check voltages from PCB and compare with service manuale. And I had already encountered a problem 🙂. Connect the ground and turn on power, put a voltmeter to 20V DC. And across the diode or anywhere else mesure 0 V. What do I do wrong? Her are pictures.
https://s24.postimg.org/jxnsffwxh/unnamed1.jpg
https://s31.postimg.org/6mde36n17/Untitled.png
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
https://s24.postimg.org/jxnsffwxh/unnamed1.jpg
https://s31.postimg.org/6mde36n17/Untitled.png
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C3402 is what is wrong. You must measure the standby supply using S9 (+ve) and MG (-ve).
You will find a power amplifier issue, probably a surround output stage as people tend to listen in stereo and get nothing from the rear channels so crank them up and when a surround sound CD/DVD is played it fries the output stage.
You will find a power amplifier issue, probably a surround output stage as people tend to listen in stereo and get nothing from the rear channels so crank them up and when a surround sound CD/DVD is played it fries the output stage.
What is S9 (+ve) and MG (-ve)? I thought the first to examine the power supply. Perhaps the voltage regulator is gone.
Is there a better quality capacitor to replace this position c3402? Are wima capacitors better? I replaced it with the first one similar thet I had at hand and look at this IT WORKS 🙂. Thank you guys! I measured the standby supply using S9 (+ve) and MG (-ve) and I can not fined referenc voltage for thet point?
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If I am reading correctly it should be about 12v at the connector. I cant see the description of C3402. Could you post a picture?
If there is absolutely no voltage to the left of the standby transformer, that one may be toast. It is always connected to mains. Maybe it took a power surge and the thermal fuse opened or something. (Measure resistance of the primary. Should normally be a few hundred ohms. I'd guess it's open.) If that is too hard to fix, an equivalent shouldn't be too hard to find, though it needs to be a center tapped one (roughly 2x 6V~ out, give or take a volt - may have to be determined experimentally).
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Hello again,
You may have to be more specific with your questions. If you do not have 10.7VAC on the left of the transformer T3401 is one problem, the cap and DC voltage is another after confirming the transformer works. Measure the resistance on both sides to see if open (no power). As noted in the schematic this transformer is temperature protected by a fuse. That one may be open. Its easier to replace that than find a new transformer.
Those fuses are imbedded in the winding. A bit of digging will reveal it.
You may have to be more specific with your questions. If you do not have 10.7VAC on the left of the transformer T3401 is one problem, the cap and DC voltage is another after confirming the transformer works. Measure the resistance on both sides to see if open (no power). As noted in the schematic this transformer is temperature protected by a fuse. That one may be open. Its easier to replace that than find a new transformer.
Those fuses are imbedded in the winding. A bit of digging will reveal it.
I'm doing something wrong! I took capacitor C3402 and measure it and it has 10 nF so it is good. So I put the black wire of the voltmeter to the G3401 and have no readings. Normally I put a voltmeter to 20V DC. But if I put the black wire of volmeter on the leg of capacitor C3402 opposite to G3401 then measure the voltage slightly higher than the reference on the site.Like on D3404 instead of 4.4V i masure 5.2V. I think I'm doing something wrong.
Transformer works. I read a bit more than the reference value. Then again I put black wire of volmeter on the leg of capacitor C3402 opposite to G3401 then measure the voltage slightly higher than the manuale on all parts except D3401. On both sides, I measured about 15v and on transistor Q3401 i measured only on middle pin 15v. And the other two pins Ov.
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