50PC1d power board

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • caspermccormack
    Senior Member
    • Mar 2012
    • 112
    • Ireland

    #41
    Re: 50PC1d power board

    I could only disconnect the bottom buffer to test the screen and the top half still had the fault while the bottom was blank.

    Comment

    • caspermccormack
      Senior Member
      • Mar 2012
      • 112
      • Ireland

      #42
      Re: 50PC1d power board

      Checked over the top and bottom buffer boards and found a mosfet on each that has shown up different readings when checked on a diode test here is what I found with all fets removed from the board.

      Black probe on the S, Red on the D = OL.
      Black probe on the S, Red on the gate to charge it
      Red back on the D =0.001, if i touch the G and D it shows up OL. again this is present on 4 of the 6 mosfets.

      One shows 0.018 each way, and one keeps going up in value instead of staying at 0.001.

      Going to change them out and see how I get on. Oh and the buffers test equally the same without the fets attached.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #43
        Re: 50PC1d power board

        Originally posted by caspermccormack
        Checked over the top and bottom buffer boards and found a mosfet on each that has shown up different readings when checked on a diode test here is what I found with all fets removed from the board.

        Black probe on the S, Red on the D = OL.
        Black probe on the S, Red on the gate to charge it
        Red back on the D =0.001, if i touch the G and D it shows up OL. again this is present on 4 of the 6 mosfets.

        One shows 0.018 each way, and one keeps going up in value instead of staying at 0.001.

        Going to change them out and see how I get on. Oh and the buffers test equally the same without the fets attached.
        The 0.018 each way sounds like a shorted FET. Try with the gate shorted to ground, i.e. off. Also, you usually need a battery (3xAA or >=4.5V) to turn the fet on; the voltage produced by your meter might not be sufficient.
        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

        • caspermccormack
          Senior Member
          • Mar 2012
          • 112
          • Ireland

          #44
          Re: 50PC1d power board

          Now that I have the 6 fets off the boards and I know one is shot may be the other 5 are weak. But heres the trouble, on the top buffer there is 3 mosfets (fairchild) G27 FQB46N15. The bottom buffer has 3 (fairchild) G26 FQB46N15.
          So whats the difference with G26 and G27? same part number?

          Called into my local Radionics and the nears they have is:

          http://radionics.rs-online.com/web/p...633D4E4F4E4526

          At that price I'd replace all 6, thats if they will work, any advice would be a great help.

          cheers.

          Comment

          • tom66
            EVs Rule
            • Apr 2011
            • 32560
            • UK

            #45
            Re: 50PC1d power board

            Originally posted by caspermccormack
            Now that I have the 6 fets off the boards and I know one is shot may be the other 5 are weak. But heres the trouble, on the top buffer there is 3 mosfets (fairchild) G27 FQB46N15. The bottom buffer has 3 (fairchild) G26 FQB46N15.
            So whats the difference with G26 and G27? same part number?

            Called into my local Radionics and the nears they have is:

            http://radionics.rs-online.com/web/p...633D4E4F4E4526

            At that price I'd replace all 6, thats if they will work, any advice would be a great help.

            cheers.
            Probably same part - different production lot code. Boards were made at a different time with slightly different parts. Wouldn't worry about it.

            That MOSFET isn't SMD, the buffer FETs probably are. I think you need TO-263/D2PAK MOSFETs.

            You will have a hard time replacing it without a hot air station too, but it may be possible with chip-quik. Never used that myself, though...
            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

            • caspermccormack
              Senior Member
              • Mar 2012
              • 112
              • Ireland

              #46
              Re: 50PC1d power board

              Click image for larger version

Name:	IMAG0261.jpg
Views:	1
Size:	204.0 KB
ID:	1904760
              These are the ones from the board.

              Comment

              • tom66
                EVs Rule
                • Apr 2011
                • 32560
                • UK

                #47
                Re: 50PC1d power board

                Originally posted by caspermccormack
                [ATTACH]38278[/ATTACH]
                These are the ones from the board.
                Glad you were able to remove them; was it difficult? Here are some replacements on digikey: http://search.digikey.com/us/en/prod...PCT-ND/2441058

                A bit more expensive, but you should only need one, as I suspect only one is shorted.
                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

                • caspermccormack
                  Senior Member
                  • Mar 2012
                  • 112
                  • Ireland

                  #48
                  Re: 50PC1d power board

                  Not to bad Tom, put on some solder and flux, held on the pad while applying pressure with a long nose pliers.

                  Do you think I should replace the lot, if they are in series and one is shorted will that weakin the others?

                  Comment

                  • caspermccormack
                    Senior Member
                    • Mar 2012
                    • 112
                    • Ireland

                    #49
                    Re: 50PC1d power board

                    Can i use the radionics parts if I solder the centre pin(drain) to the pad that the original fet was soldered to??

                    Comment

                    • tom66
                      EVs Rule
                      • Apr 2011
                      • 32560
                      • UK

                      #50
                      Re: 50PC1d power board

                      Originally posted by caspermccormack
                      Can i use the radionics parts if I solder the centre pin(drain) to the pad that the original fet was soldered to??
                      Not really, as it wouldn't have adequate heatsinking and might overheat.
                      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

                      • tom66
                        EVs Rule
                        • Apr 2011
                        • 32560
                        • UK

                        #51
                        Re: 50PC1d power board

                        Originally posted by caspermccormack
                        Do you think I should replace the lot, if they are in series and one is shorted will that weakin the others?
                        Whichever one is shorted needs replacement.

                        If they are in parallel you can do a quick hack: cut the source pin. There will now only be two FETs but it should work for 5 minutes. Don't use it for too long, as it may burn the other FET. This assumes they are in parallel - are they? Check this beforehand.
                        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

                        • caspermccormack
                          Senior Member
                          • Mar 2012
                          • 112
                          • Ireland

                          #52
                          Re: 50PC1d power board

                          Originally posted by tom66
                          Not really, as it wouldn't have adequate heatsinking and might overheat.
                          Thats what I taught!! I'll order from the post you had earlier.
                          I'd of scraped this project only for your help!!! cheers.

                          Comment

                          • caspermccormack
                            Senior Member
                            • Mar 2012
                            • 112
                            • Ireland

                            #53
                            Re: 50PC1d power board

                            Replaced the 6 fets on the buffer boards and tv started up like new, delighted with it, trimmed the voltages to spec on the board but the tv shuts off after 10 to 20 minutes with a loud pop, it will switch back on straight away and stay on for another 10 or 20 minutes??? I checked the temp on the service menu and it only got to 22.Click image for larger version

Name:	IMAG0317.jpg
Views:	1
Size:	280.0 KB
ID:	1905596

                            Click image for larger version

Name:	IMAG0316.jpg
Views:	1
Size:	249.5 KB
ID:	1905597

                            Click image for larger version

Name:	IMAG0318.jpg
Views:	1
Size:	208.3 KB
ID:	1905598

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK

                              #54
                              Re: 50PC1d power board

                              Originally posted by caspermccormack
                              Replaced the 6 fets on the buffer boards and tv started up like new, delighted with it, trimmed the voltages to spec on the board but the tv shuts off after 10 to 20 minutes with a loud pop, it will switch back on straight away and stay on for another 10 or 20 minutes??? I checked the temp on the service menu and it only got to 22.[ATTACH]39508[/ATTACH]

                              [ATTACH]39509[/ATTACH]

                              [ATTACH]39510[/ATTACH]
                              AC detect okay?
                              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

                              • caspermccormack
                                Senior Member
                                • Mar 2012
                                • 112
                                • Ireland

                                #55
                                Re: 50PC1d power board

                                What do i look out for to check its ok?

                                Comment

                                • tom66
                                  EVs Rule
                                  • Apr 2011
                                  • 32560
                                  • UK

                                  #56
                                  Re: 50PC1d power board

                                  Originally posted by caspermccormack
                                  What do i look out for to check its ok?
                                  Check the voltage at ACD.

                                  I have had the loud pop come from an LG 42PC1D when the PSU suddenly shuts down. It comes from the speakers.
                                  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

                                  • caspermccormack
                                    Senior Member
                                    • Mar 2012
                                    • 112
                                    • Ireland

                                    #57
                                    Re: 50PC1d power board

                                    I'll take a look at the ac detect in the morning, Yeah loud pop from the speakers as it goes into standby. I am hoping i'm not to far from getting this tv back to working 100%. I have changed out the hybrid on the 42" and so far so good, not that bad to change it if you take your time.

                                    Cheers Tom.

                                    Casper.

                                    Comment

                                    • caspermccormack
                                      Senior Member
                                      • Mar 2012
                                      • 112
                                      • Ireland

                                      #58
                                      Re: 50PC1d power board

                                      The Tv has being on all morning and afternoon and no faults???? Think I'll stick the back on and put it back on the wall, hope the f--k it's ok.

                                      Comment

                                      • tom66
                                        EVs Rule
                                        • Apr 2011
                                        • 32560
                                        • UK

                                        #59
                                        Re: 50PC1d power board

                                        Originally posted by caspermccormack
                                        The Tv has being on all morning and afternoon and no faults???? Think I'll stick the back on and put it back on the wall, hope the f--k it's ok.
                                        Rule 1 of troubleshooting: A problem that goes away by itself will come back by itself.
                                        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

                                        • caspermccormack
                                          Senior Member
                                          • Mar 2012
                                          • 112
                                          • Ireland

                                          #60
                                          Re: 50PC1d power board

                                          The extension lead I was using during testing has a loose connection, its worked all day pluged into the wall.

                                          Comment

                                          Related Topics

                                          Collapse

                                          • Tynan Dill
                                            Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                            by Tynan Dill
                                            I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                            Upon bringing it home and plugging it up, it showed a standby light.

                                            I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                            The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                            With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                            Assuming...
                                            11-22-2024, 01:46 PM
                                          • Destroyer-Br
                                            [HELP] Acer AN515-55 (LA-J871P Rev: 1B) – Board won't power on after GPU investigation – Suspecting Super I/O or PCH
                                            by Destroyer-Br
                                            [HELP] Acer AN515-55 (LA-J871P Rev: 1B) – Board won't power on after GPU investigation – Suspecting Super I/O or PCH

                                            Hi everyone,

                                            I'm working on an Acer Nitro 5 unit with the following specs:
                                            • Motherboard: LA-J871P Rev: 1B
                                            • Model: Acer AN515-55-59MT
                                            • S/N: NHQ7JAL00403906A973400
                                            • SNID: 03902728734

                                            Initial Issue


                                            The laptop initially presented graphic issues and driver failure (Code 43) for the GPU.

                                            After preventive maintenance (cleaning, thermal paste, etc.), it powered on normally. We disassembled it again to inspect the GPU, reassembled...
                                            04-17-2025, 08:18 PM
                                          • Dani_2024
                                            Sceptre U550CV-UMR 4K LED, Bad Caps on Main Power Board?
                                            by Dani_2024
                                            Hi and thanks in advance for any input you might provide!
                                            I have a Sceptre U550CV-UMRD8POTV83BB 4K LED (this is a dumb tv) that I bought new in August 2021, so It's just completed 3 years.
                                            Main power board model: TP.MS3683.PC821 T-Con board: N4TP546UHDPU2L_BO

                                            Last Sunday I was watching a dvd and fell asleep for about half hour, when I awoke the tv screen was black and couldn't get the dvd menu to show, so I changed the input to antenna and had sound but no picture, turned it off. I then got online and found this great site! ....read many troubleshooting tips and this...
                                            10-28-2024, 05:06 PM
                                          • sam_sam_sam
                                            Panasonic switching power supply daughter board has two 27uf @ 50 volt capacitors which I do not keep in stock
                                            by sam_sam_sam
                                            I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow

                                            This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board

                                            After all of...
                                            07-13-2024, 08:14 PM
                                          • sam_sam_sam
                                            Tankless hot water heater controller board not powering up when power is applied
                                            by sam_sam_sam
                                            I recently bought a used tankless hot water heater and the controller board is completely dead no power up when power is applied the display board works however the main controller board does not work correctly at all the fuse is good

                                            I bought a used replacement controller board that also had issues that I was able to fix and now the tankless water heater works correctly now

                                            However I would like to know if I could figure what happened to this controller board if possible

                                            Tomorrow I will take some better pictures of both side of both boards

                                            The...
                                            12-09-2022, 09:14 PM
                                          • Loading...
                                          • No more items.
                                          Working...