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Emerson lf461em4 mainboard troubleshooting

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    Emerson lf461em4 mainboard troubleshooting

    Hi guys, I have an Emerson lf461em4 TV that is dead. I checked voltages as far as I could figure out and the power supply appears to be good. There is no standby light when plugged in. I assumed that I should be seeing a red standby light at the bottom front.

    I have parts from a Dynex DX-32L200NA14 that I had saved away in case I find one with a good screen that I can part swap.
    I noticed that the the mainboards are very different but have the same cable ports.
    Not a wise decision but I went ahead and plugged the Dynex mainboard in the Emerson TV without the LCD cable to see what happens.
    I plug it into the wall and I get a red standby light. Interesting. I can go further.
    Uplugged it and then plugged in the LCD cable, plugged into the wall again, then turned it on.
    Backlights on, I see channel 3.1 on the screen,
    So that told me that the power supply should be ok even though the mainboard is from a 32", the screen works, no cracks, backlights work, buttons work. I pressed menu and it shows the options but of course the screen is upside down and the colors, sizes are way off.
    That's ok, I was just troubleshooting to see what isn't working.
    So the mainboard I assume is my problem.
    I put the Emerson mainboard back in.
    From there I looked up what I could find on the mainboard, I checked the capacitor at C3214 and it is not shorted. I checked capacitor C3832, C3833 and the two small ones there with them.
    IC3601 had 2.5v, the other 1117s had 3.3. I assume it was in standby when I checked it since I get no lights or anything.

    Anything else that I can check?
    EEPROM bad?

    Also, there is a QR code sticker over the serial number and below that sticker is another one with a different serial number. It starts with RS2A. The Original under the QR code starts with a DS2A

    Thanks
    Last edited by Eel_dahc; 06-11-2018, 04:23 PM. Reason: spelling

    #2
    Re: Emerson lf461em4 mainboard troubleshooting

    Nah, eeprom wont have anything to do with the stand by LED not working. SJ makes a main board repair kit for these( out of stock of course), the symptom it fixes includes a dead set.

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      #3
      Re: Emerson lf461em4 mainboard troubleshooting

      Originally posted by CapLeaker View Post
      Nah, eeprom wont have anything to do with the stand by LED not working. SJ makes a main board repair kit for these( out of stock of course), the symptom it fixes includes a dead set.
      Ok, thanks

      Comment


        #4
        Re: Emerson lf461em4 mainboard troubleshooting

        There's the out of stock repair kit, you could check that diode with your meter, wouldn't it be a nice surprise if it was just a bad diode, probably not tho. http://www.shopjimmy.com/emerson-a3a...lf461em4-a.htm

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          #5
          Re: Emerson lf461em4 mainboard troubleshooting

          Originally posted by nomoresonys View Post
          There's the out of stock repair kit, you could check that diode with your meter, wouldn't it be a nice surprise if it was just a bad diode, probably not tho. http://www.shopjimmy.com/emerson-a3a...lf461em4-a.htm
          Thanks, I'll have to look out for that.

          I checked every part that looked like those in the kit pics, of course no part numbers but just going on the packages and everything seemed ok. The diode though, I wasn't sure about. Might have to lift it and check, because it had readings going both ways but they differed. I am more familiar with schottky one ways.
          Last edited by Eel_dahc; 06-13-2018, 03:48 PM.

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            #6
            Re: Emerson lf461em4 mainboard troubleshooting

            For sure, when in doubt lift it out.

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              #7
              Re: Emerson lf461em4 mainboard troubleshooting

              Hey guys I have this same tv with the same problem as post#1( no power). I also tried a similar main board from another emerson and the tv turned on. So I suspected a main board issue also. Now, I put the old main back in and voila, the tv turned on. Worked fine for 2 1/2 days, then went out again. Ok so I took the back off to listen for beeps and/or get some voltages, but the tv turned on again. Any suggestions whats causing this malfunction?

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                #8
                Re: Emerson lf461em4 mainboard troubleshooting

                cold solder joint somewhere maybe?

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