Magnavox 47MF437B blowing fuse

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  • therev
    New Member
    • May 2012
    • 2
    • USA

    #1

    Magnavox 47MF437B blowing fuse

    Hello everyone I could use some help. To start with my LCD tv was working fine but over the past few months it would turn off on its own. The remote would not tun it back on. I would have to turn it off and back on at the tv and it would come back on. The other day it did it again but would not come back on. I took it apart and seen 1 capacitor swollen and the 6.3 amp AC fuse blown. I replaced four capacitors and the fuse. As soon as I plugged the tv in to the outlet the fuse blew. Where should I go from here its all new to me. I have an automotive electrical background not this type but enjoy learning. Any help greatly appreciated.
  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #2
    Re: Magnavox 47MF437B blowing fuse

    Can you take some pictures of your board and post them? Up to 2000x2000 pixels size - closer the better. Use macro mode and a sunny day for best results.

    The main causes of the fuses blowing are:
    - Bridge rectifier shorted
    - Power MOSFET shorted

    Usually when the second happens, a few other components are damaged (on PSU), but it is still repairable.

    Magnavox/Philips TVs have crap capacitors (saving pennies at the customer's expense) so the caps failing are probably unrelated. What replacement capacitors did you use - where did you get them, what manufacturer/series, capacitance, voltage?

    Do you have a multimeter - I assume if you work with automotive electronics you do?
    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #3
      Re: Magnavox 47MF437B blowing fuse

      One of these service manuals may match your chassis:
      http://elektrotanya.com/?q=showresul...oria=&kat2=all
      Attached Files
      Last edited by budm; 05-03-2012, 03:18 PM.
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

      Comment

      • therev
        New Member
        • May 2012
        • 2
        • USA

        #4
        Re: Magnavox 47MF437B blowing fuse

        OK, thanks for the quick responses. I'm going to try and post pic's. As far as the caps I replaced I do not know what brand they are. I went to our local tv repair shop with my old ones and asked if he had any replacements. He then provided me with replacements tellingme they were exactly what I needed.
        Having trouble uplocading my pic's the system keeps informing me the upload failed. Im going to have to review the pic upload process.
        Also I do have a multimeer, I have a Fluke 88

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #5
          Re: Magnavox 47MF437B blowing fuse

          See if the PDF I provided match your power supply module, that will make it easier to troubleshoot the problem.
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

          Comment

          • psmedley
            Senior Member
            • Apr 2012
            • 144
            • Australia

            #6
            Re: Magnavox 47MF437B blowing fuse

            Originally posted by therev
            Having trouble uplocading my pic's the system keeps informing me the upload failed. Im going to have to review the pic upload process.
            Pictures need to be <= 2000x2000 resolution, and under 2mb - otherwise the upload will fail....

            Comment

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