Help on repair Yamaha RX-V496 - won't turn on

Discussion in 'Electronics Repair' started by Amaro Leandro, May 19, 2017.

  1. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Hello!
    I'm brazilian and firstly please sorry for my english.

    I came to tell my sad story hahaha

    My son spitted juice on my receiver. At the same time I shut off the equipment.
    After the clean there is not powering on. Going on protection mode but show the info percent from DC protection.
    Ok. Looked at superficially I found some resistors opened. Removed and soldered the new but at the moment in connect the cables, I've inverted some connections (images 1 and 2) and since then the receiver not display anything (only horizontal lines for 0.5sec).
    I hear the relay arming and desarming rapidly.

    With tests on the power supply, the line that should have AC12v (image 3), have AC24v. I don't know if it's the problem.

    Can anyone help me in this problem?
    Thank you in advance for your support.
     

    Attached Files:

    • 1.PNG
      1.PNG
      File size:
      154.7 KB
      Views:
      29
    • 2.PNG
      2.PNG
      File size:
      47.7 KB
      Views:
      24
    • 3.PNG
      3.PNG
      File size:
      83.1 KB
      Views:
      27
    Amaro Leandro, May 19, 2017
    #1
    1. Advertisements

  2. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    anyone?
     
    Amaro Leandro, May 24, 2017
    #2
    1. Advertisements

  3. Amaro Leandro

    KilgoreCemetery

    Joined:
    Apr 12, 2017
    Messages:
    55
    Likes Received:
    6
    Location:
    Probably in my chair
    I would definitely recommend not powering the unit on again until we can figure out how to get the AC24v back down to AC12v
     
    KilgoreCemetery, May 25, 2017
    #3
  4. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Thanks for the reply!
    Any tips for repairing the transformer in order to reduce the voltage to AC12v?
     
    Amaro Leandro, May 26, 2017
    #4
  5. Amaro Leandro

    KilgoreCemetery

    Joined:
    Apr 12, 2017
    Messages:
    55
    Likes Received:
    6
    Location:
    Probably in my chair
    Actually, after reading this post, it sounds like a transformer may be able to put out a lot more voltage than I would have guessed while not under load.

    Let's start over a bit. What's the model number of the receiver?
     
    KilgoreCemetery, May 26, 2017
    #5
    Amaro Leandro likes this.
  6. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Sure. My model it's the RX-V496 Model R.
    I watched some videos from receiver repairs but not evolved in that.

    Here is some information about what I visualized after the occurred:

    - The receiver are powered on and shutdown automaticaly after 2secs. Starting with the hotkeys pressed, the lcd showed DC values and powered off;
    - I Substituted some resistor and nothing;
    - Then I connected the cables inverted (3 ways: 2 +RYV and 1 VPB) and the state worsened;
    - Now the equipment power on and power off at the same moment. The LCD blink.

    Thanks for the help and attention.
     
    Amaro Leandro, May 27, 2017
    #6
  7. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Update:
    I have tested the voltages in all power supply parts and they are ok
    However, I identified some voltage in PRV. Can be it. I'm going continue studying the circuit for kill this problem.

    Thanks for any tip you can give me.
     
    Amaro Leandro, May 29, 2017
    #7
  8. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Update:
    I found a problem on cap.el. 4700uf/5.5v from display board. The lines are from 5v and this tension drops to 4.5v when the receiver is power on.
    I measured the capacitor in 8.8v, in/out of board.

    I going buy a new and reinstall. I'll inform.
     
    Amaro Leandro, May 30, 2017
    #8
  9. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Replacing the capacitor not resolved the problem. :(
     
    Amaro Leandro, May 31, 2017
    #9
  10. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Update
    I have analised the pins from IC501 and found the next values:

    Pin 12 - RESET - 4.8V (OK);
    Pin 16 - VCC - 4.8V (OK);
    Pin 20 - PDT (Power down detect input) - 4.8V (4.0V is the correct);
    Pin 40 - PRI (Over current protection detect input) - 0V (OK);
    Pin 46 - PRY (Power relay output) - 4.8V (OK);
    Pin 63 - VCC - 4.8V (on manual the right is -29,3V, but the why I not understand);
    Pin 90 - LIMDT (Limitter DC detect input) - 0.6V (0.2V is the correct);
    Pin 91 - PRV (PS protection) - 3.0V (1.5V is the correct);
    Pin 92 - PRD (DC protection) - 0.9V (0.3V is the correct).

    Anyone have any idea what to look or change?
     
    Amaro Leandro, Jun 2, 2017
    #10
  11. Amaro Leandro

    Amaro Leandro

    Joined:
    May 19, 2017
    Messages:
    9
    Likes Received:
    0
    Update:
    I was able to connect and keep the equipment on, disconnecting the flat going to the voltage regulators.
    I believe that the reversal of the cable I made may have damaged the central IC. The voltage outputs for image generation on the display do not provide more than 1.5V even when the equipment is turned on.

    I'm giving up on getting it back.
     
    Amaro Leandro, Jun 7, 2017
    #11
    1. Advertisements

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads
  1. John Miller

    Magnavox TV won't turn off, then won't turn on

    John Miller, Apr 17, 2004, in forum: Electronic Repair
    Replies:
    3
    Views:
    2,643
    John Miller
    Apr 17, 2004
  2. Pat
    Replies:
    1
    Views:
    1,106
    Sofie
    Sep 8, 2006
  3. Arfa Daily

    Re: Yamaha receiver RX-V992 RX-V995 won't stay on

    Arfa Daily, Jan 6, 2009, in forum: Electronic Repair
    Replies:
    1
    Views:
    3,524
    news.kc.sbcglobal.net
    Jan 6, 2009
  4. Bob E.

    Yamaha RX-V992 won't power on

    Bob E., Mar 10, 2013, in forum: Electronic Repair
    Replies:
    10
    Views:
    1,488
    Bob E.
    Mar 13, 2013
  5. genghis80

    Yamaha RX V2607 amplifier won't power up

    genghis80, Dec 25, 2014, in forum: General Electronics Chat
    Replies:
    2
    Views:
    732
    genghis80
    Jan 14, 2015
  6. Danielle E Abbott

    Phillips model 32pfl3403D/27 won't turn on

    Danielle E Abbott, Sep 20, 2016, in forum: Electronics Repair
    Replies:
    1
    Views:
    217
    davenn
    Sep 20, 2016
  7. KilgoreCemetery

    Insignia TV won't turn on

    KilgoreCemetery, Apr 12, 2017, in forum: Electronics Repair
    Replies:
    16
    Views:
    376
    KilgoreCemetery
    Apr 24, 2017
  8. benyboy981

    Led turn on when car interior lights turn on

    benyboy981, May 14, 2017, in forum: Circuit Help
    Replies:
    5
    Views:
    125
    benyboy981
    May 15, 2017
Loading...