YAMAHA RX-V775 Strange Problem

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • benja1475
    Member
    • May 2012
    • 26
    • Philippines

    #1

    YAMAHA RX-V775 Strange Problem

    Hi... Good day to all and Happy New Year... I have a Yamaha RX-V775 and I have some strange problem, I update it to the latest version (1.93) via Internet. I notice some strange behavior with my unit after the update. First, I notice that the unit will not remember his last mode (e.g. if you turn off the AVR while in radio mode, by the time you turn it ON again will display that he is in radio mode) but now it won't, it will always be in TV mode. Second, it will cycle Tone Control Setting (bass, trebble) by it's own, and sometimes sound is cut-off (no sound) but the unit is still ON and it's not responsive, you can't control the AVR. I notice that the unit is not responsive if theirs no sound, but still the unit is ON and in the LCD display Tone Control setting cycle itself. It happen in random, Tone Control Setting cycle by itself then sound is cut off, sometimes Tone Control Setting cycles itself but sound is ok. The most strange thing I notice is... you can now turn ON/OFF the unit by pressing Tone Control button in the front panel and sometimes pressing the MAIN power switch button will not power the unit, but pressing the Tone Control button will turn it ON without miss, and also very strange that while the unit is ON, you can cycle the Tone Control Setting by pressing the MAIN power switch button (main power switch is suppose to be just to turn ON/OFF the unit... hhmmmmm). I reset the AVR to factory setting, but worse thing happen, standby led will not light, but you can still turn ON/OFF the unit by either MAIN switch or the Tone Control button, and more worse issssssss... any of the buttons except Tone Control (which is now the power key) will cycle the Tone Control Settings. So I decided to download a new copy of the firmware (v1.93) from yamaha website and re-flash the unit via USB, because maybe I think the update via internet is not doing good (but I think it's done successfully because I still use the unit for several days until I notice the first symptom, "not remember the previous mode") but still the problem is the same. Any help is very much appreciated... thank you
    Last edited by benja1475; 01-08-2018, 11:02 PM.
  • Longbow
    Badcaps Veteran
    • Jun 2011
    • 623
    • USA

    #2
    Re: YAMAHA RX-V775 Strange Problem

    After flashing the firmware you should get a message saying that the flash is successful. If so, you don't have a firmware problem and it won't be fixed by doing another update. First, do the factory reset (somewhere in the manual usually). Second, I would start looking for water damage or some reason that the display/front panel button micro isn't working. That might appear as one of the button scan lines missing (shorted, open). Does the unit behave badly with the remote AND the front panel equally?

    Also try this: put the remote control in a drawer, and at the same time place some black tape over the remote sensor window. The remote might be transmitting continuously, or florescent lighting may be falsely triggering the unit. Just a thought.
    Is it plugged in?

    Comment

    • benja1475
      Member
      • May 2012
      • 26
      • Philippines

      #3
      Re: YAMAHA RX-V775 Strange Problem

      Thank you for your reply, I decided to open the unit because I notice some trace of mice urine in the AVR top cover... unfortunately some of it went through the air vent and to digital board, IC83, IC921 and it's surrounding components are wet, not much but i think its enough to cause some problem. I clean it with denatured alcohol and after blow drying for several minutes... after an hour i test the unit, its thesame.

      Comment

      • Longbow
        Badcaps Veteran
        • Jun 2011
        • 623
        • USA

        #4
        Re: YAMAHA RX-V775 Strange Problem

        That figures. That's why the symptoms always change from day to day. There is no way to fix it, unless you can get a spare board from another unit.
        Is it plugged in?

        Comment

        Related Topics

        Collapse

        • zen
          Drill control unit switch required ,help please
          by zen
          Hi all , it's part of a control unit that operates a drill.


          Striped it down & cleaned contacts but not reliable

          Hoping some one out there in the ethos can help me source one . ( see pictures )...
          05-16-2024, 03:49 AM
        • nzphil
          Yamaha YST-C10 stereo capstans run for 10 min when unit is turned on
          by nzphil
          I have a Yamaha YST-C10 mini-stereo that was made around 1990. It has two cassette decks, a CD player and an AM/FM tuner. When it is turned on in tuner mode, the cassette deck capstans normally run for about one second and then the radio will begin to play. Currently, however, the capstans run continuously for about five minutes followed by running intermittently in two second bursts for another five minutes. The radio will play softly when the capstans stop during the intermittent phase. After about 10 minutes of this, the capstans stop completely and all the stereo functions work fine.
          ...
          04-11-2021, 05:58 PM
        • ngml
          Repair of an LG split AC system indoor unit PCB
          by ngml
          I am trying to repair an LG split AC indoor unit, which does not start and gives a CH05 error code.
          This indicates an error in the communication between the outdoor and the indoor unit.
          The outdoor unit is fine, so the problem is the indoor PCB.
          The indoor unit is an LG PC09SQ NSJ (3SNM09JA2FA), and the PCB has the following type number: EAX35907219-1.2 (see photo1)
          I changed optocouplers ICO1X & ICO2X and the NPN transistor S9013 which drives optocoupler ICO2X (see photo2), but this did not remedy the fault.

          Does anybody have the schematics of this board,...
          02-01-2025, 12:55 PM
        • bauto601
          KDM 480W PSU upgrade succes! (opinions?)
          by bauto601
          Back in 2020 i bought a (2nd hand) compact ATX psu to replace my current one. My PC case only fits very short ATX power supplies so i didn't really have the choice of buying a decent 80Plus unit. The current unit is a modded YoungYear unit that i made a thread about a while ago:
          A "nice" YoungYear unit? - Badcaps

          The "new" unit is a KDM-M6480 480W psu, the 480W number is a typical KDM bullshit claim of course, but the 24A rating on the 12V rail seemed reasonable and the "Active PFC" claim gave me a bit of hope that this was going to be decent-ish....
          12-26-2023, 03:05 PM
        • Yanleb
          LG 60PK550 Logic Control Board EBR63450301
          by Yanleb
          Hi all, I just want to share the repair of my 60PK550-UA TV set.

          The TV set was powering on, just no image. After verification, nothing wrong on the YSus or ZSus boards. Nothing wrong on the main board either.

          But I noticed that the LED was not flashing on the Logic Control Board. This is an EBR63450301. The LED is supposed to flash even with all the flat cables disconnected, with only the power cable attached.

          All the voltages measured at the electrolytic capacitors on the board were good. From top left to bottom right:
          C57: 3.30V
          C61:...
          07-20-2023, 12:38 AM
        • Loading...
        • No more items.
        Working...