Yamaha RX-V 775 power supply

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • MONST1
    New Member
    • Nov 2022
    • 4
    • Germany

    #1

    Yamaha RX-V 775 power supply

    Hi, as the titel says iam actually working on a Yamaha vsx-r775 power supply.

    When i received the receiver it was completly dead. So after a visiual inspection and starting meassurments, i quickly found out that the 5V supply voltage is missing. My futher investigations lead me to the IC STR-Y6753, because the VCC was just add 2V instead of 16V. After that i`ve checked every component from the VCC circut but couldnt found any faulty components. So i concluded that the startup circut from the chip itself is broken and should be replacet first.

    After searching on the Internet for a replacement, i found out that the STR-Y6766 version(which i already had) could be an equivalent for the 6753. I`ve checked the datasheeds and couldnt find any problems to just give it a try.

    So i replaced the 6753 and things did not go as planned. Ad startup VCC is present for about 3 sec., then the IC is shutting down and ideling ad 11.3V. According to the datasheet, this should mean that the bias assist prevent a startup failure(protection / stand-by on the fb pin=0.8V).

    i thought meassuring the fb pin on startup should be the next step. On startup its about 4V for 3sec., after that it goes high to 6.96V(datasheet= OLP threshhold). I checkd the transformer and parts around on the output side but couldnt find any thing. Thats the point where im struggeling at the moment and i hope sompebody got a suggestion of what to do next.

    KR
    Attached Files
    Last edited by SMDFlea; 11-05-2022, 09:51 AM. Reason: RX-V 775 not vsx-r775
  • lotas
    Badcaps Legend
    • Jan 2016
    • 4620
    • Russia

    #2
    Re: Yamaha vsx-r775 power supply

    So do you have a Yamaha or a Pioneer? (vsx -xxx for Pioneer, rx -xxx for Yamaha).

    Comment

    • MONST1
      New Member
      • Nov 2022
      • 4
      • Germany

      #3
      Re: Yamaha vsx-r775 power supply

      It's a Yamaha RX-V 775

      Comment

      • SMDFlea
        Super Moderator
        • Jan 2018
        • 21022
        • UK

        #4
        Re: Yamaha RX-V 775 power supply

        thread title edited: Yamaha RX-V 775 power supply
        All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

        Comment

        • R_J
          Badcaps Legend
          • Jun 2012
          • 9551
          • Canada

          #5
          Re: Yamaha RX-V 775 power supply

          Replace C3708 to start with, Check R3704 as it may have been damaged if the internal mosfet was shorted.
          Last edited by R_J; 11-05-2022, 10:51 AM.

          Comment

          • MONST1
            New Member
            • Nov 2022
            • 4
            • Germany

            #6
            Re: Yamaha RX-V 775 power supply

            I have already replaced both C3708 and R3704, unfortunately without success.

            Comment

            Related Topics

            Collapse

            • sam_sam_sam
              Desoldering gun station modified to use a 18 volt @ 20 amp switching power supply
              by sam_sam_sam
              I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump

              One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy...
              03-31-2024, 02:12 PM
            • Tynan Dill
              Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
              by Tynan Dill
              I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

              Upon bringing it home and plugging it up, it showed a standby light.

              I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

              The screen seems to blackout and stay black, but with a flashlight I can see the display.

              With my Playstation 4 connected via HDMI, and running a game I can hear sound.

              Assuming...
              11-22-2024, 01:46 PM
            • sam_sam_sam
              Modification to a ZD-987 desoldering/soldering station using a external switching power supply
              by sam_sam_sam
              I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails

              I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time...
              07-01-2024, 06:34 AM
            • shamsudeen
              Hi, Can we use SMPS Bench Power Supply for Laptop troubleshooting?
              by shamsudeen
              Hi all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
              I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.

              i know that in linear power supply the noise will be very low comparing to SMPS supply....
              07-19-2025, 07:14 AM
            • tritron
              yamaha rx-a2a bad stanby power supply
              by tritron
              I got yamaha rx-a2a and there is no power no stanby led. I was poking arround
              power supply and shlotsky diod is bad. I get beep of continity. The part has
              marking m3405 08 d5409 on board. What replacement I can buy for it ? What elese could be shorted out with those diods ?
              06-04-2023, 08:39 PM
            • Loading...
            • No more items.
            Working...