2s to black. Proscan 32LB30Q

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  • culcuhain
    Senior Member
    • May 2016
    • 186
    • U$@

    #1

    2s to black. Proscan 32LB30Q

    Ok. I have a Proscan 32LB30Q on the bench this morning.
    I have all the correct voltages on the main board. (5vstby, 5Vpwron, have BLON and DIM)
    I think I have narrowed it down to the Inverter Board or the Lamps.
    I have attached a few pics with the voltages.
    I am not sure how to test the primary side of the inverter. The secondary side (inner posts/bindings) I get 24.6V. I have 24.6v on all sides of the white fuses (F1-F4). I did not see a black Fuse anywhere on the board.
    Inverter board is I315B1-16A-C302G.
    All the voltages stay the same when going from standby to On except the error on the inverter, it spikes to 154mvish and then drops back down to the 50mv range.
    If I need to test the inverter, please share a link (couldn't find one in the search) or walk me through it if possible.
    I have learned a lot over the past few weeks and I appreciate everyone's help. Thank you!!!
    Attached Files
  • culcuhain
    Senior Member
    • May 2016
    • 186
    • U$@

    #2
    Re: 2s to black. Proscan 32LB30Q

    If I use the cfl bulb tester that budm shows us how to make and connect it to test each output and the backlights come on then that means bad bulb and if not then bad board? Or is there a better to determine if the inverter board is bad or the bulbs?

    Comment

    • dick_barton
      Badcaps Legend
      • Aug 2015
      • 6642
      • Wales

      #3
      Re: 2s to black. Proscan 32LB30Q

      Here's a link to a thread on this site.

      https://www.badcaps.net/forum/showth...sting+inverter
      Willing to help but I'm no expert.

      Comment

      • culcuhain
        Senior Member
        • May 2016
        • 186
        • U$@

        #4
        Re: 2s to black. Proscan 32LB30Q

        Awesome! That is what I am looking for! Looks like I will be starting at step 4 as I have already done the previous steps!

        Comment

        • culcuhain
          Senior Member
          • May 2016
          • 186
          • U$@

          #5
          Re: 2s to black. Proscan 32LB30Q

          I think I have a bad inverter board.
          I have 24.xVDC across all fuses.
          I have 24VDV at the primary side input and output on all the inverters.
          When hooking up a CFL bulb to each CFL connecter (keeping all others connected) it lights up but I still have 2s to black. Voltages steady on input side and output side.
          I am getting a bad IC, shorted SMD Diode. Part order and we shall see....

          Comment

          • ReeceyBurger123
            Never Give Up !
            • May 2014
            • 7325
            • Britain

            #6
            Re: 2s to black. Proscan 32LB30Q

            Sounds like a failed transformer to me, do you know how to test them ?
            Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

            https://www.facebook.com/Telford-Tel...7894576335359/

            Comment

            • culcuhain
              Senior Member
              • May 2016
              • 186
              • U$@

              #7
              Re: 2s to black. Proscan 32LB30Q

              I read in the links provided earlier in the post. I have up to 20% variance betweeen all 8.

              Comment

              • dick_barton
                Badcaps Legend
                • Aug 2015
                • 6642
                • Wales

                #8
                Re: 2s to black. Proscan 32LB30Q

                From memory I believe that anything over 3% is considered as bad.
                Willing to help but I'm no expert.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #9
                  Re: 2s to black. Proscan 32LB30Q

                  Originally posted by culcuhain
                  I read in the links provided earlier in the post. I have up to 20% variance betweeen all 8.
                  Can you show which pins you use for testing the resistance of the inverter transformer, and what reading did you get?
                  BTW, there are two high voltage windings for each transformer.
                  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

                  • culcuhain
                    Senior Member
                    • May 2016
                    • 186
                    • U$@

                    #10
                    Re: 2s to black. Proscan 32LB30Q

                    using this as a guide: http://www.lcdparts.net/TransformerD...ProductID=3497

                    P1-P2: 0.8 Ohm
                    P3-p4: 0.8 ohm
                    S1-S2: 1.022-1026 Kohms
                    S3-S4: 1.032-1.036 Kohms except 1... It was 1.154K ohms

                    Bad inverter?

                    Comment

                    • budm
                      Badcaps Legend
                      • Feb 2010
                      • 40746
                      • USA

                      #11
                      Re: 2s to black. Proscan 32LB30Q

                      Sound like you do have one bad inverter transformer.
                      Last edited by budm; 07-24-2016, 10:20 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

                      • culcuhain
                        Senior Member
                        • May 2016
                        • 186
                        • U$@

                        #12
                        Re: 2s to black. Proscan 32LB30Q

                        Inverter replaced and Backlights stay on. Victory!

                        Comment

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