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Sony kdl-42w705b no video no audio vertical stripes

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    Sony kdl-42w705b no video no audio vertical stripes

    I need help on how to run the screen test mode by the service menu without seeing the video out, entering SM is easy but after i know i have to press Option 2 times to go to the VCP part, then i have to access menu 005, this by pressing "2" 5 times i think and then? There'no explanation on service manual about this Test pattern menu, what i have to press? Thankyou so much bye bye.

    #2
    Re: Sony kdl-42w705b no video no audio vertical stripes

    Originally posted by Davi.p View Post
    I need help on how to run the screen test mode by the service menu without seeing the video out, entering SM is easy but after i know i have to press Option 2 times to go to the VCP part, then i have to access menu 005, this by pressing "2" 5 times i think and then? There'no explanation on service manual about this Test pattern menu, what i have to press? Thankyou so much bye bye.
    If the 42" panel is AUO or anything like the 50" version, panel has probably crapped itself. Got a 50" here, totally disgusted and having read up a bit, seems common failure and about 3 years is it.

    another reason I still love my panasonic, plasma, I can fix the boards, panels are generally pretty solid.

    I'm hanging on for Tv with the same panel to do a rebuild.

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      #3
      Re: Sony kdl-42w705b no video no audio vertical stripes

      The bad panel is major percentage, but i need to be sure, usually vertical lines have an image under them, here there isn't. I don't know if i can try the trick of lvds cable detached, externally supplied 12v and jump 3,3v<>pin41 like some LG panels.. i have to try with a bad panel that i have first..

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        #4
        Re: Sony kdl-42w705b no video no audio vertical stripes

        Hi, i was inspecting the tcon 'cause i have some hopes about it and when i was testing the usual voltages i found a cooked resistor, a boubble on top of it and boubbles around it on the pcb, despite of this it measures good for what i can see, the marking was slightly visible, it was 1R80, it is part, for what i can recognize, of a charge pump power supply for the VGL, that it measures a bit high for me (-4,8v), the Res. go to a condenser that measures 225nF detached, that goes in the middle of a series of 2 identical power low drop (0,167v) diodes, one with cathode to GND, the other with anode to a big transistor that goes to VGL testpoint. The other voltages are correct apart VGH that is low (11v). VGL is near a multipin AUO chip that is its controller i think and that produces also AVDD and is for me half toasted, in the other side of the card there's another AUO chip that produces VGH from a normal boost converter (big inductance visible). I don't know why also VGH is bad but i think the pwm of its controller is keep off by a control in the chain of the voltages that senses the bad VGL.. I'm here to ask you if i'm good if i feed from external a good VGL around -6 or -7v to see what happens? Bye..

        Ah, forget it, the cooked resitor measures 12v and 0hm to the 12Vin of the board..
        also the question is odd since the voltage control is made probably or surely by the same chip i suppose cooked..
        Last edited by Davi.p; 10-22-2017, 05:46 PM.

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          #5
          Re: Sony kdl-42w705b no video no audio vertical stripes

          Sorry, very inexperiened with LCD but I can say I swapped a good Tcon into a bad panel not knowing watched it cook in a another AUO panelled TV.

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            #6
            Re: Sony kdl-42w705b no video no audio vertical stripes

            thanks, i found a bad Linear regulator, it's sot23-3 and i don't find the right marking code equivalence for now (25FS1, maybe S1 is production lot).

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              #7
              Re: Sony kdl-42w705b no video no audio vertical stripes

              Anyway if someone can tell me the Vout of this reuglator i thank him very much.. now i'm stuck on it, it's easy to find the pin assignment, but the Vout is at least impossible. One can connect an external DC-DC reg and trim it live but i think is not the only piece broken on this board.

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                #8
                Re: Sony kdl-42w705b no video no audio vertical stripes

                I found a very little hole in the second tensions generator(+buffers) chip, so i have ordered a new tcon from China, all the tcon in the market are from another tv model so i have to swap the eproms before start. Also bought the chips..

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                  #9
                  Re: Sony kdl-42w705b no video no audio vertical stripes

                  Originally posted by tw2005 View Post
                  and about 3 years is it.
                  Sounds just like the motherboards during the classic bad caps motherboard era! Especially during the single core era. Eww!
                  Last edited by RJARRRPCGP; 10-23-2017, 04:44 PM.
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                    #10
                    Re: Sony kdl-42w705b no video no audio vertical stripes

                    The tv is 3 years..

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