magnavox 37MF321D/37 no power

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  • johnboy1313
    Badcaps Legend
    • Nov 2012
    • 1959
    • USA
    #21
    Re: magnavox 37MF321D/37 no power

    Every set that I've fixed had that chip go bad. Do a search for IC7003 or LD5973D there is a capacitor that may need to be replaced as well.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA
        #22
        Re: magnavox 37MF321D/37 no power

        https://www.badcaps.net/forum/showth...ghlight=IC7003
        Read post 23 about bad cap.
        and this one by Johnboy:
        https://www.badcaps.net/forum/showth...light=l5973%2A
        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

          • rsrace
            Member
            • Dec 2015
            • 13
            • United States
            #23
            Re: magnavox 37MF321D/37 no power

            Many thanks Johnboy and BudM. I think I will take a shot at the IC7003 replacement (and the associated capacitor). At the price of the main boards available right now, this seems like the way to go.

            I will also check the outputs of the IC to be sure that nothing is shorted...both boards look like they fried right between pin 7 and 8 as shown in many of those other posts I found in BudM's reply and a search I did of the forum.

            Originally posted by johnboy1313
            Those chips are cheap and easy to replace. Buy two chips and a heat gun. Fix both boards, use one, and sell the other.
            I like the way you think Johnboy - I need to recoup a bit from this ordeal and it would be nice to sell a verified-working main board to help.

            When you say heat gun - do you mean an industrial "hair drier" like is used for shrink wrap and such (I have one)? Is that to release the IC from the circuit board? I assume I do not need to seat the new one with heat as that would likely overheat the IC...?

            I also saw a tip on another post from BudM to cut the legs off the IC first to make removal easier.

              Comment

              • rsrace
                Member
                • Dec 2015
                • 13
                • United States
                #24
                Re: magnavox 37MF321D/37 no power

                Nailed it! All is working now after replacing IC 7003 and capacitor 2002!

                One of the two main boards I "fixed" did not have any standby after replacing the IC, so I need to go back and figure out what I messed up (because that's a change from low volts). I bought one extra IC and cap from digikey so I might just have to start the soldering over again.

                The other board fired right up and I have picture and power lights again...it has been running for hours now.

                Many thanks BudM and Johnboy1313 ...I could not have done this without you!

                  Comment

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