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E390vl help with regulator testing

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    #61
    Re: E390vl help with regulator testing

    Will I be able to test the resistance when it's removed from the board like that. And not connected at all to the tv.

    Comment


      #62
      Re: E390vl help with regulator testing

      We want to test resistance of the output copper pad and the chassis ground without having the IC on the board, we are not trying to measure the resistance of the IC.
      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


        #63
        Re: E390vl help with regulator testing

        Ahhhhhhhh. That makes so much sense. Super blonde moment. Haha

        Comment


          #64
          Re: E390vl help with regulator testing

          So I removed the regulator and the big pad or output pad still read 1.1ohms. Here is a pict of the board with the regulator removed.
          Attached Files

          Comment


            #65
            Re: E390vl help with regulator testing

            Originally posted by audiofreak19 View Post
            So I removed the regulator and the big pad or output pad still read 1.1ohms. Here is a pict of the board with the regulator removed.
            you can remove the inductor to confirm (see picture) if your CPU is fried. This will isolate the regulator output from the CPU.Then measure the output again. I only did a visual trace of that output of that regulator, you may need to confirm where that regulator output is feeding by using your multimeter in continuity mode. also try testing the cap.
            Attached Files
            Last edited by ecking767; 05-11-2014, 07:46 PM.

            Comment


              #66
              Re: E390vl help with regulator testing

              So if I remove the inductor. I should get the same ohm reading? What would it say if the CPU was bad.

              Comment


                #67
                Re: E390vl help with regulator testing

                Is there a small brown rectangular ceramic connected to the big tab of the IC also? Removing that FB (ferrite bead) from the circuit will help us isolate the load from the output pad, there may be more than one load that is connected to the output pad, removing that FB is the start.
                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


                  #68
                  Re: E390vl help with regulator testing

                  The only think small I can see that's near the output tabs is that very time cp18 if you look just left of the 3 pads.

                  Comment


                    #69
                    Re: E390vl help with regulator testing

                    Ok I see the fb it's what eclogues labeled in his image. I will remove that and take another resistance measurement of the big tab in ref to ground.

                    Comment


                      #70
                      Re: E390vl help with regulator testing

                      Wow I ment ecking

                      Comment


                        #71
                        Re: E390vl help with regulator testing

                        CP18 looks like for the input. Typical kook up of the regulator IC will have electrolytic cap with small ceramic cap in parallel for the input pin and the same for the output pin.
                        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


                          #72
                          Re: E390vl help with regulator testing

                          Ah ok.

                          Comment


                            #73
                            Re: E390vl help with regulator testing

                            BTW, the small brown ceramic cap usually is MLCC (Multi Layer Ceramic Capacitor), when it failed, it failed as shorts circuit.
                            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


                              #74
                              Re: E390vl help with regulator testing

                              Ok so I took the small ceramic cap out the fb whatever. And measured the resistance between the out put pin and the chassis ground without the tv plugged in and got 5.78 mega ohms. So I'm guessing the CPU chip is bad. Eh?

                              Comment


                                #75
                                Re: E390vl help with regulator testing

                                That or any other components that are connected to that section.
                                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


                                  #76
                                  Re: E390vl help with regulator testing

                                  What would you say to check next. I might just buy another main cause I found one on ebay for 35. But I like learning how to test these things and how each of these components work.

                                  Comment


                                    #77
                                    Re: E390vl help with regulator testing

                                    Remove CPU see if short goes away )

                                    Comment


                                      #78
                                      Re: E390vl help with regulator testing

                                      There has to be another MLCC cap after the FB, I would look for that and then remove it to see if shorts will go away.
                                      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


                                        #79
                                        Re: E390vl help with regulator testing

                                        And sorry for my ignorance I'm having a blonde moment. But a short on my multimeter would be a lot of resistance correct?

                                        Comment


                                          #80
                                          Re: E390vl help with regulator testing

                                          Also was the FB thing the MLCC cause there is a very small cap next to the FB thing I removed.

                                          Comment

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