Yamaha RX-797 part 1

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  • Опубліковано 11 лис 2024

КОМЕНТАРІ • 9

  • @mtbarr64
    @mtbarr64 Місяць тому

    In case no one has responded the unit is WORKING. Turn off the "CD Direct" and the other botton. When in "CD Direct" mode the unit TURNS OFF THE DISPLAY. I noted you never used this unit when working. The MASTER button is the main power which puts the unit into "Standby" mode with NO display. When you hit the bigger button the unit actually powers on, with the DISPLAY being the key indicator that it is working!
    So this unit was FIXED Thanks for the detailed troubleshooting. I will be doing my own shortly.

  • @johanragnarsson9310
    @johanragnarsson9310 Рік тому +1

    The master is the on/ off button, the other one is for standby

  • @johanbotha9889
    @johanbotha9889 Рік тому +1

    I don't know if you have the same problem I've had, but the Yamaha I worked on was kind of doing the same as what this one is doing. The relay energizes and after a few seconds it de energize. I couldn't hear if your relay de energizes, but if it does I suspect capacitor (C254) is faulty which was in my case the problem. The ESR was too high and it caused for the optocoupler (IC251) not to pull the 5V (+5M) on the detect (DET) circuit to ground. As you can see if the circuit is healthy you should read 0.2V at the collector of the optocoupler (IC251) and not 5V.

  • @TheDefpom
    @TheDefpom Рік тому

    Still early on in the video but my guess is C259 being off value, it is a capacitive dropper, low capacitance will result in lower voltage to the bridge. C254 is also a suspect.

  • @izzzzzz6
    @izzzzzz6 Рік тому +1

    That 3.4 and 3.7V on the 2nd bridge rec is confusing as. If you measured the ac side from a dc ground would you see 3.4 and 3.7 dc on a DMM? You must be one of the only people who has not already heard about the failing cap across the relay is it c259 on this one?

  • @АльпПромСамара
    @АльпПромСамара 10 місяців тому

    Hello! Please explain why you installed this mosfet (ipan60r600)? In according to its voltage characteristics, the drain-source voltage is only 20 volts maximum, but on the schematic diagram of power supply shows a value of minus 29 volts?!

    • @JonnyFix
      @JonnyFix  7 місяців тому +1

      Datasheet says Vds is 650V max. Vgs is 20. Now that I look again original Vgs was 30. Ooops. For what it's worth, the unit is still in operation and I know the guy so if it fails again I'll change it up. Maybe Vgs doesn't quite hit that high.

    • @mtbarr64
      @mtbarr64 Місяць тому

      @@JonnyFix Still a DAMN good job that you did! You need a MOSFET tester. I just happen to have one. I will let you know if my issue is the same and will test it on the tester. Thanks again for the WORK and video.

    • @JonnyFix
      @JonnyFix  Місяць тому +1

      @@mtbarr64 Thanks, glad you like it! I have a mosfet tester now to :)