Panny TC-P50G25 bad SC board -- what else to check?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • AnthonyC
    Member
    • Oct 2017
    • 10
    • USA

    #1

    Panny TC-P50G25 bad SC board -- what else to check?

    Thanks to the troubleshooting guide on this forum and many threads, I diagnosed a bad SC board on my Panasonic plasma TV. Dead short on the Vsus line to the SC board. Other boards connecting to power showed good resistance.

    No obvious damage to the board (scorch marks, cracked components, bulging caps). I checked the screws, since that was mentioned as a problem and they all seemed tight with no discoloration or other indications of arcing.

    Original symptom was the TV worked in the morning. In the afternoon, I heard the relays click, then click again, and no picture. It was blinking a four blink code.

    First -- anything else to check as to why the SC board failed short? I'd hate to repair/replace and have this happen again.
    Second -- self repair or send it out? I'm pretty good at soldering macro-size components but have no experience with surface mount. So I'm leaning towards paying for a repair.

    Is PTS Electronics still the go-to for this? I saw them recommended a lot in other threads.

    Thanks all!
    Anthony
  • Moreno83
    Badcaps Legend
    • Jun 2014
    • 2008
    • The Netherlands

    #2
    Re: Panny TC-P50G25 bad SC board -- what else to check?

    What board do you got?

    Usually the FETS get shorted. Check the components marked with "Q". ( For example Q661 ).

    Meter in diode/continuity mode and propes on outer legs. ( black on left leg , red on right and reverse ). Beep is bad.

    Same with the parts labeled with "D". They are diodes but you need to measure them differently. Black prope on middle leg and red on left/right leg.
    I only repair Panasonic plasma tv's! Currently owning a TX-P55VT50 and still searching for a ZT60!

    Comment

    • tw2005
      Badcaps Legend
      • Oct 2011
      • 6458
      • Australia

      #3
      Re: Panny TC-P50G25 bad SC board -- what else to check?

      Originally posted by AnthonyC
      Thanks to the troubleshooting guide on this forum and many threads, I diagnosed a bad SC board on my Panasonic plasma TV. Dead short on the Vsus line to the SC board. Other boards connecting to power showed good resistance.

      No obvious damage to the board (scorch marks, cracked components, bulging caps). I checked the screws, since that was mentioned as a problem and they all seemed tight with no discoloration or other indications of arcing.

      Original symptom was the TV worked in the morning. In the afternoon, I heard the relays click, then click again, and no picture. It was blinking a four blink code.

      First -- anything else to check as to why the SC board failed short? I'd hate to repair/replace and have this happen again.
      Second -- self repair or send it out? I'm pretty good at soldering macro-size components but have no experience with surface mount. So I'm leaning towards paying for a repair.

      Is PTS Electronics still the go-to for this? I saw them recommended a lot in other threads.

      Thanks all!
      Anthony
      You could try the repair, most large kits probably cover the known bad bits, safest way is get it done if you're happy with the cost.

      Check the sd/su are still ok and not shorted. Then give the ol girl a pat and thank her for giving you 7 solid years .

      Why they fail, they do. Mine failed at 18 months and 2500 hrs. I now have 18000 hrs still waiting for another failure. One thing I noticed with mine (Rev AF) was some earth pads were missing topside compared to other boards I'd seen. WHO knows.

      generally there are no loose bolt issues it's the 2011 models that changed the bolt type.

      I just picked up one with only 4500hrs, blown sc. Looks like it's sat under the house for a few years. popped a spare in and she's all beautiful again.

      Considering the issues with LED backlights eg LG and TVs with lenses falling off and burning out in 2 years. I think the panasonic plasma has better durability and repairability. Bit hard on the Kilowatts that's all.

      Comment

      • AnthonyC
        Member
        • Oct 2017
        • 10
        • USA

        #4
        Re: Panny TC-P50G25 bad SC board -- what else to check?

        I have a 5081AF SC board.

        I'll take a look at the Q's and diodes.

        How do I check the sd/su for shorts? Specifically, which connectors and pins should I check?

        Thanks guys.

        Comment

        • heavymachines
          Badcaps Legend
          • Mar 2011
          • 1028
          • United States

          #5
          Re: Panny TC-P50G25 bad SC board -- what else to check?

          https://www.youtube.com/watch?v=-JVLWpcIxJQ watch this basically same procedure to testing any buffer boards on any plasma.
          Last edited by heavymachines; 10-24-2017, 07:17 PM.

          Comment

          • AnthonyC
            Member
            • Oct 2017
            • 10
            • USA

            #6
            Re: Panny TC-P50G25 bad SC board -- what else to check?

            Question: which way is bad for the diodes to read? I was measuring middle out (black middle, then red on either of the legs). It seemed like they all beeped on both legs when I did that.

            The FETs were another matter:

            Q402 L/R short
            Q403 L/R short
            Q421 L/R short
            Q422 L/R short
            Q441 Okay
            Q442 Okay
            Q452 L/R short
            Q621 Okay
            Q622 L/R short
            Q660 Good


            Checking buffer boards now.

            Thanks.

            Comment

            • AnthonyC
              Member
              • Oct 2017
              • 10
              • USA

              #7
              Re: Panny TC-P50G25 bad SC board -- what else to check?

              Do I have to take the ribbons off to check the SD/SU boards? Seems like I could do more harm than good if I didn't have to.

              Comment

              • heavymachines
                Badcaps Legend
                • Mar 2011
                • 1028
                • United States

                #8
                Re: Panny TC-P50G25 bad SC board -- what else to check?

                Originally posted by AnthonyC
                Do I have to take the ribbons off to check the SD/SU boards? Seems like I could do more harm than good if I didn't have to.
                best to test them by themselves so no false readings youtube how to do this safely and effectively its not hard to do.

                Comment

                • AnthonyC
                  Member
                  • Oct 2017
                  • 10
                  • USA

                  #9
                  Re: Panny TC-P50G25 bad SC board -- what else to check?

                  I also saw there is another row of pins under the ribbons. Just finished checking them and very carefully putting the ribbons back in.

                  No shorts to ground on any of the ribbons, so I'm hoping it's good there.

                  Comment

                  • heavymachines
                    Badcaps Legend
                    • Mar 2011
                    • 1028
                    • United States

                    #10
                    Re: Panny TC-P50G25 bad SC board -- what else to check?

                    Originally posted by AnthonyC
                    I also saw there is another row of pins under the ribbons. Just finished checking them and very carefully putting the ribbons back in.

                    No shorts to ground on any of the ribbons, so I'm hoping it's good there.

                    If done right should be ...

                    Comment

                    • heavymachines
                      Badcaps Legend
                      • Mar 2011
                      • 1028
                      • United States

                      #11
                      Re: Panny TC-P50G25 bad SC board -- what else to check?

                      Originally posted by AnthonyC
                      Question: which way is bad for the diodes to read? I was measuring middle out (black middle, then red on either of the legs). It seemed like they all beeped on both legs when I did that.

                      The FETs were another matter:

                      Q402 L/R short
                      Q403 L/R short
                      Q421 L/R short
                      Q422 L/R short
                      Q441 Okay
                      Q442 Okay
                      Q452 L/R short
                      Q621 Okay
                      Q622 L/R short
                      Q660 Good


                      Checking buffer boards now.

                      Thanks.
                      Depends on the of diode type. plenty of youtube vids , 3 legged diodes etc, zener, etc

                      Comment

                      • AnthonyC
                        Member
                        • Oct 2017
                        • 10
                        • USA

                        #12
                        Re: Panny TC-P50G25 bad SC board -- what else to check?

                        I was more interested if these inparticular were supposed to be middle-out or outside-in for direction. It was late last night and I did not get a good look at the diode case markings. I'll give it a more thorough try tonight.

                        Where can I source the FETs? I tried the part numbers in Digikey and it came up blank. SJ has 5 packs of some parts, but were out of stock. Just wondering where else to look.

                        Comment

                        • tw2005
                          Badcaps Legend
                          • Oct 2011
                          • 6458
                          • Australia

                          #13
                          Re: Panny TC-P50G25 bad SC board -- what else to check?

                          Originally posted by AnthonyC
                          I was more interested if these inparticular were supposed to be middle-out or outside-in for direction. It was late last night and I did not get a good look at the diode case markings. I'll give it a more thorough try tonight.

                          Where can I source the FETs? I tried the part numbers in Digikey and it came up blank. SJ has 5 packs of some parts, but were out of stock. Just wondering where else to look.
                          You better read my TNPA5081 thread, There's some surface work and ICs needed too generally. Keep in mind if this goes wrong you won't be able to send that board to anyone.
                          Last edited by tw2005; 10-25-2017, 12:37 PM.

                          Comment

                          • AnthonyC
                            Member
                            • Oct 2017
                            • 10
                            • USA

                            #14
                            Re: Panny TC-P50G25 bad SC board -- what else to check?

                            I'm about 10% into that thread now. I'll keep at it, though. Thanks for the help.

                            Still leaning towards PTS. Just want one more day to take a look at things before committing.

                            Comment

                            • heavymachines
                              Badcaps Legend
                              • Mar 2011
                              • 1028
                              • United States

                              #15
                              Re: Panny TC-P50G25 bad SC board -- what else to check?

                              Originally posted by AnthonyC
                              Where can I source the FETs? I tried the part numbers in Digikey and it came up blank. SJ has 5 packs of some parts, but were out of stock. Just wondering where else to look.

                              List the numbers and someone will list a compatible one that will work.

                              Comment

                              • AnthonyC
                                Member
                                • Oct 2017
                                • 10
                                • USA

                                #16
                                Re: Panny TC-P50G25 bad SC board -- what else to check?

                                I caved and sent it to PTS. They got it Monday and I got it back today. Plugged her in and it fired up nice. I looked at the menu and it appears all lines look fine. I'll plug it into the cable box and see full video to verify.

                                Thanks for the help. Even though I didn't do the soldering, it was nice to know I had the bad board isolated and what was wrong with it.

                                Comment

                                • tw2005
                                  Badcaps Legend
                                  • Oct 2011
                                  • 6458
                                  • Australia

                                  #17
                                  Re: Panny TC-P50G25 bad SC board -- what else to check?

                                  Originally posted by AnthonyC
                                  I caved and sent it to PTS. They got it Monday and I got it back today. Plugged her in and it fired up nice. I looked at the menu and it appears all lines look fine. I'll plug it into the cable box and see full video to verify.

                                  Thanks for the help. Even though I didn't do the soldering, it was nice to know I had the bad board isolated and what was wrong with it.
                                  not a bad idea, stress free. look at that, identified the bad bit sent it in, rebuilt, installed watching telly

                                  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
                                  • m1ch43lzm
                                    HP Pavilion 15-eh Board DAG7HAMB8F0 - CPU throttling to 0.4GHz (PROCHOT_EXT) and black screen
                                    by m1ch43lzm
                                    Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
                                    Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic...
                                    05-12-2025, 08:37 PM
                                  • Hakuu
                                    LG OLED77G1PUA - No Video / Audio after a TCON Board change and Software Update
                                    by Hakuu
                                    Hi There,

                                    This TV was auto switching off after few seconds with some vertical lines on the screen, so got a new TCON board and replaced it.

                                    After replacing the TCON board it was working fine and i set it up with everything, used for few hours, then had the bright idea to update the software on it. During the update process, TV switched off and now no audio or video. No relay switch sound.

                                    More Details

                                    TV Model - LG OLED77G1PUA

                                    Got the same exact TCON board from TVPartsToday and replaced it. But didnt transfer the EPPROM data (didnt...
                                    07-12-2023, 02:37 PM
                                  • MacGyver's paperclip
                                    what to check before replacing hybrid MOSFET/controller IC on SAMSUNG TV power board
                                    by MacGyver's paperclip
                                    TLDNR; Have an old SAMSUNG TV with blown hybrid MOSFET/controller IC on power board to be replaced; replaced blown main capacitor on same power board several years ago successfully, and TV has been working fine since until this IC popped all of a sudden. Want to know what if anything to check on board to make sure before replacing and testing with new IC. Have 2 new matching ICs, DIP socket to make removal/replacement easier, a whole other known-good power board with which to compare, if necessary.
                                    07-01-2023, 12:12 PM
                                  • canadaboy25
                                    Panasonic TC-P54VT25 No image. A or D board?
                                    by canadaboy25
                                    I have a Panasonic TC-P54VT25 that will power on and prime the display but there is no image at all.

                                    The panel is primed as there is a slight glow from the entire panel. This means the problem should be logic related. The service manual also confirms this and recommends replacing the A or the D board.

                                    I have tried to get the TV to display the test sequence but I have been unable to and I don't even know if this TV has a test sequence or not. I tried following tom66's instructions in post #3 on this thread https://www.badcaps.net/forum/showthread.php?t=26790. There was...
                                    01-17-2021, 01:06 AM
                                  • Loading...
                                  • No more items.
                                  Working...