Lcd tv power supply producing a high pitched and static noise. No picture but sound.

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  • efan
    Member
    • Sep 2012
    • 30
    • CANADA

    #21
    Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

    fuses as shown in picture
    Attached Files

    Comment

    • retiredcaps
      Badcaps Legend
      • Apr 2010
      • 9271

      #22
      Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

      Originally posted by budm
      B+ of 36 Volt seems very high.
      Agreed.

      @funtastic, you want to measure DC voltage with your black probe on either a ground screw on the t-con or chassis.
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      If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

      We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

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      Comment

      • funtastic
        Senior Member
        • Nov 2012
        • 63
        • New Zealand

        #23
        Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

        Hi There,

        I've tested all four of the white fuses and they are fine, and tested other components, and the caps. Everything is receiving around 36v. The black fuse is the one that has blown.

        Shall I buy the same fuse as on this thread? https://www.badcaps.net/forum/showthread.php?t=17214. Seems like the same fuse.

        Do you think 36v is to high? What would cause a higher output?

        One other thing is that the fan above the power supply isn't working. I checked the connector and it's not receiving power, or is it one that switches on when it gets to a certain temp?


        Thanks all for the help.

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #24
          Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

          I expect that black fuse to be bad, very common on this CMO board. I use through hole PICOII fuse by just bending the legs. One end of the fuse is connected to the 24V input, you can just trace another end to the solder pad that the other end of the fuse is connected to. You should verify you meter first with know good batteries such as car batteries.
          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

          • funtastic
            Senior Member
            • Nov 2012
            • 63
            • New Zealand

            #25
            Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

            Thanks for that. I replaced the multimeter battery and it's now 24v.

            Could you please link me to the fuse to get on Digikey please? The label of this fuse is F 1A/76v.

            Comment

            • funtastic
              Senior Member
              • Nov 2012
              • 63
              • New Zealand

              #26
              Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

              Will this be fine? http://www.ebay.com/itm/10pcs-Littel...item5d35fbb91e

              Would like an answer please to my previous question about the fan.

              Thanks

              Comment

              • funtastic
                Senior Member
                • Nov 2012
                • 63
                • New Zealand

                #27
                Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                Anybody?

                Comment

                • funtastic
                  Senior Member
                  • Nov 2012
                  • 63
                  • New Zealand

                  #28
                  Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                  With the PICO Fuse is there a positive and negative or can it be put on any way?

                  Comment

                  • budm
                    Badcaps Legend
                    • Feb 2010
                    • 40746
                    • USA

                    #29
                    Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                    There is no polarity in the fuse. That one on EBAY is the type I use. I get my from Mouser, but Digikey also sell them.
                    http://s807.photobucket.com/albums/y...%20Littlefuse/

                    What is the smallest value resistor in 1/4 w size you have? If you have anything less than 1 Ohm, you can use that for testing for now. Not sure about the fan.
                    Last edited by budm; 12-06-2012, 07:30 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

                    • funtastic
                      Senior Member
                      • Nov 2012
                      • 63
                      • New Zealand

                      #30
                      Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                      Hi All,

                      I replaced the fuse and the back light flicks on for a second and then turns off again but the picture and sound are still on.

                      What else could be wrong?

                      Comment

                      • tom66
                        EVs Rule
                        • Apr 2011
                        • 32560
                        • UK

                        #31
                        Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                        One of the transformers or bulbs could be faulty.
                        Do the transformers have a part code on them?
                        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                        Comment

                        • funtastic
                          Senior Member
                          • Nov 2012
                          • 63
                          • New Zealand

                          #32
                          Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                          Hi All,

                          Thanks for every ones help . Turns out that I forgot to plug in a tiny connector on the inverter and now everything works like new.


                          Thanks

                          Comment

                          • funtastic
                            Senior Member
                            • Nov 2012
                            • 63
                            • New Zealand

                            #33
                            Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                            Hi, the fan connector isn't receiving power and was wondering if it was possible to connect the wires up to somewhere else on the circuit boards?

                            The connector is the one at the top right of pic.
                            Attached Files

                            Comment

                            • budm
                              Badcaps Legend
                              • Feb 2010
                              • 40746
                              • USA

                              #34
                              Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                              Did the fan always run before the TV broke down? May be it is on only when the sensor senses too much heat?
                              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

                              • funtastic
                                Senior Member
                                • Nov 2012
                                • 63
                                • New Zealand

                                #35
                                Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                Hi, I bought it with it not working. I thought that too so I left it going for 2 hours and it felt quite hot and still the fan hadn't come on so I'm unsure whether it wasn't hot enough or there's something wrong. Maybe I should leave it going for longer and see what happens.

                                If it still doesn't come on is there a place that I could wire it in? strip two of the wires of the ones connecting to that board?


                                Thanks

                                Comment

                                • budm
                                  Badcaps Legend
                                  • Feb 2010
                                  • 40746
                                  • USA

                                  #36
                                  Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                  Does the FAN has two wires or 3 wires? Voltage and current rating on the Fan?
                                  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

                                  • funtastic
                                    Senior Member
                                    • Nov 2012
                                    • 63
                                    • New Zealand

                                    #37
                                    Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                    3 wires but the third is just the speed reading correct? 12V and 0.09A

                                    Comment

                                    • funtastic
                                      Senior Member
                                      • Nov 2012
                                      • 63
                                      • New Zealand

                                      #38
                                      Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                      Not sure if you need these reading but thought I'd list them.

                                      Top left connector

                                      1. 12.39
                                      2. 0.00
                                      3. 0.00
                                      4. 0.00
                                      5. 15.21
                                      6. 0.00
                                      7. 6.18

                                      Next connector down

                                      1. 0.00
                                      2. 11.11
                                      3. 0.00
                                      4. 5.00
                                      5. 0.00
                                      6. 1.74
                                      7. 0.00
                                      8. 3.27
                                      9. 0.00
                                      10. 5.00
                                      11. 0.00
                                      12. 0.00
                                      13. 4.87
                                      14. 4.87

                                      Comment

                                      • funtastic
                                        Senior Member
                                        • Nov 2012
                                        • 63
                                        • New Zealand

                                        #39
                                        Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                        Don't worry about it now I connected the fan to the first connector onto the first two pins and it's working great.


                                        Thanks

                                        Comment

                                        • budm
                                          Badcaps Legend
                                          • Feb 2010
                                          • 40746
                                          • USA

                                          #40
                                          Re: Lcd tv power supply producing a high pitched and static noise. No picture but sou

                                          Glad it works out, failed TV due to 50 cent fuse on the inverter board.
                                          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

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