50PA4500 safety

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  • Jkirk3279@gmail.com
    New Member
    • Aug 2019
    • 3
    • USA
    #1

    50PA4500 safety

    I have the back off the TV, the red light is constantly clicking...

    I was wondering if the clicking relay was on the Power board, and leaned closer.

    I got a healthy shock when I tapped the central heatsink bar.

    About sixty volts AC.

    Just curious if this is normal, or if stray voltage means the board is hosed.

    Thanks.
    Tags: None
    • stj
      Great Sage 齊天大聖
      • Dec 2009
      • 31083
      • Albion
      #2
      Re: 50PA4500 safety

      heatsinks are often live in some way, because they are in contact with metal components.

        Comment

        • R_J
          Badcaps Legend
          • Jun 2012
          • 9553
          • Canada
          #3
          Re: 50PA4500 safety

          Yes that is normal, the heatsink is likely connected to hot ground on the primary side of the power supply, and it can sit at about half the a/c line voltage.

            Comment

            • CapLeaker
              Leaking Member
              • Dec 2014
              • 8210
              • Canada
              #4
              Re: 50PA4500 safety

              that is why you are supposed to be really careful in the hot section of the PSU. Always take measurements first if you are not sure.

                Comment

                • SLK001
                  Badcaps Veteran
                  • May 2014
                  • 264
                  • USA
                  #5
                  Re: 50PA4500 safety

                  Originally posted by Jkirk3279@gmail.com
                  I got a healthy shock when I tapped the central heatsink bar.

                  ...

                  Just curious if this is normal, or if stray voltage means the board is hosed.

                  Thanks.
                  Yes, it is normal that if you fix broken TVs, you will often receive a healthy shock. You will get used to it.

                    Comment

                    • Jkirk3279@gmail.com
                      New Member
                      • Aug 2019
                      • 3
                      • USA
                      #6
                      Re: 50PA4500 safety

                      Originally posted by R_J
                      Yes that is normal, the heatsink is likely connected to hot ground on the primary side of the power supply, and it can sit at about half the a/c line voltage.
                      Oh, of course.

                      My blood sugar must have been low, I knew that.

                      Thanks.

                      I was just worried that more than the cap was bad.

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA
                          #7
                          Re: 50PA4500 safety

                          You should at least plug what ever you are working on into the GFCI outlet.
                          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

                            • Packard93
                              Senior Member
                              • Jul 2016
                              • 81
                              • United States
                              #8
                              Re: 50PA4500 safety

                              Always use safety when working in tv. It will have two sides on the power supply board hot and cold. HOT SIDE IS AC AND COLD IS DC. OR IT WILL SAY PRIMARY FOR AC AND SECONDARY FOR DC ON THE PCB LOOK FOR WHITE LINE .TV VOLTAGE CAN KILL SO DONT touch the hot and primary on any pcb. There live discharge is about 30 mins but not all capacitors can hold charge even after 30mins .
                              Last edited by Packard93; 08-07-2019, 02:02 PM.

                                Comment

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