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Dead Vestel 17IPS71 power board

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    Dead Vestel 17IPS71 power board

    Help please working on a Busy tv I have had give which I believe may have suffered a power surge
    Power board seems completely dead no standby light no output voltages that i can find
    Input fuse FS1 on board is ok

    Anyone any ideas where to start looking now
    I know I can just change the board plenty on ebay but would like to at least try and find out what is wrong with this board
    will take some pics of the board and post them asap

    #2
    Re: Dead Vestel 17IPS71 power board

    17IPS71 power board
    Attached Files

    Comment


      #3
      Re: Dead Vestel 17IPS71 power board

      Have you checked what voltages there are across C19, C20, C21 with the meter set to 600V and measure across the two pins of each capacitor in turn.
      Willing to help but I'm no expert.

      Comment


        #4
        Re: Dead Vestel 17IPS71 power board

        Also check the diodes.

        Comment


          #5
          Re: Dead Vestel 17IPS71 power board

          748v on each cap C19/20/21

          Comment


            #6
            Re: Dead Vestel 17IPS71 power board

            any particular diodes to check, are we checking for voltage at diodesor shorts across diodes

            Comment


              #7
              Re: Dead Vestel 17IPS71 power board

              Originally posted by london-freddie View Post
              748v on each cap C19/20/21
              The readings are incorrect. The capacitors are only rated at 400V DC!!!
              Willing to help but I'm no expert.

              Comment


                #8
                Re: Dead Vestel 17IPS71 power board

                just checked again def showing 747/8 v at + & - legs of caps

                Comment


                  #9
                  Re: Dead Vestel 17IPS71 power board

                  There's no way the voltage across the legs of each capaitor in turn is as high as you say without damage. They are only rated at 400V. It should be somewhere around 340V dc
                  Willing to help but I'm no expert.

                  Comment


                    #10
                    Re: Dead Vestel 17IPS71 power board

                    meter set at 600V AC red probe on +ve leg black probe on -ve leg 747 or 748v on all three caps if that makes any sense

                    Comment


                      #11
                      Re: Dead Vestel 17IPS71 power board

                      Originally posted by london-freddie View Post
                      meter set at 600V AC red probe on +ve leg black probe on -ve leg 747 or 748v on all three caps if that makes any sense
                      DC Voltage measurement please.
                      Willing to help but I'm no expert.

                      Comment


                        #12
                        Re: Dead Vestel 17IPS71 power board

                        am i doing this right ?
                        Attached Files

                        Comment


                          #13
                          Re: Dead Vestel 17IPS71 power board

                          ah 336V DC

                          Comment


                            #14
                            Re: Dead Vestel 17IPS71 power board

                            senior moment i think

                            Comment


                              #15
                              Re: Dead Vestel 17IPS71 power board

                              Thanks. So you have rectified DC so now to find out why you have no DC outputs.
                              Could you measure the dc voltage on CN3-CN4 (black connector) with the mainboard disconnected and see if there is at least a standby voltage?
                              Willing to help but I'm no expert.

                              Comment


                                #16
                                Re: Dead Vestel 17IPS71 power board

                                no voltages at all at CN3/4 connector

                                Comment


                                  #17
                                  Re: Dead Vestel 17IPS71 power board

                                  I don't know how close this schematic is but it's time to start checking components.
                                  There are a lot of 0 Ohm resistors that I would check as well.
                                  Attached Files
                                  Willing to help but I'm no expert.

                                  Comment


                                    #18
                                    Re: Dead Vestel 17IPS71 power board

                                    sorry but would not know where to start looking

                                    Comment


                                      #19
                                      Re: Dead Vestel 17IPS71 power board

                                      Checked the output diodes for S/C ?
                                      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


                                        #20
                                        Re: Dead Vestel 17IPS71 power board

                                        Please watch my video, yes its a different Psu but same concept:

                                        https://m.youtube.com/watch?v=owmBcJ91yJw
                                        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

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