Panasonic G20 Failure :/

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • Falco21
    Member
    • Jun 2012
    • 10
    • United States

    #1

    Panasonic G20 Failure :/

    New member here. Been on forums for a long time.

    I currently have a 50" Panasonic G20 Plasma. TC-P50G20

    It is about 2 years old and has worked flawlessly. The other night I was watching TV and when I shut it off, I heard a pop noise. Tried to turn it back on and now all it does is attempt to turn on, then turn itself off. The red LED light blinks 10 times. I replaced the Power Board and the Video Board, still with the same issue. The only board I have not touched is the Y Board. Does anyone know what could be causing this?
  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #2
    Re: Panasonic G20 Failure :/

    Service manual: (wait 30 seconds until "Get Manual" appears below image preview.)

    Diagnosis procedure for 10 blinks (page 17) indicates the following boards possibly at fault:

    A-Board (you've probably replaced this, it's the board with the inputs)
    SC-Board (Y board)
    SS-Board (Z/X board)
    P-Board (replaced)

    Faults are: Sub 5V SOS, Sub 3.3V SOS, Sub 9V SOS, Tuner Power SOS.

    Do you have a multimeter?

    The pop noise to me suggests SC or SS boards.
    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

    • Falco21
      Member
      • Jun 2012
      • 10
      • United States

      #3
      Re: Panasonic G20 Failure :/

      Originally posted by tom66
      Service manual: (wait 30 seconds until "Get Manual" appears below image preview.)

      Diagnosis procedure for 10 blinks (page 17) indicates the following boards possibly at fault:

      A-Board (you've probably replaced this, it's the board with the inputs)
      SC-Board (Y board)
      SS-Board (Z/X board)
      P-Board (replaced)

      Faults are: Sub 5V SOS, Sub 3.3V SOS, Sub 9V SOS, Tuner Power SOS.

      Do you have a multimeter?

      The pop noise to me suggests SC or SS boards.
      I just ordered the SC Board this morning.

      And yes, I do have a multi-meter. What do you need me to check?

      Thank you for your help!!
      Last edited by Falco21; 06-06-2012, 02:30 PM.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #4
        Re: Panasonic G20 Failure :/

        Originally posted by Falco21
        The SC, which is also labeled as the Y Board, and the SS-Board are the same correct? I just purchased the SS board and it also says it is the Y Board.
        No, they are different boards. The SC board is the SCan board, and it controls the buffers to produce the picture on the screen. With a malfunctioning SC board you will get -no picture- if there is no short.

        The SS board does not scan the screen. It is the Second Sustain (that's how I like to remember it, it probably stands for something entirely different.) With a malfunctioning SS board you will get a picture but it will be very poor (dim, slow, blurry, sometimes purple-tinted.)

        However the most common failure on both is a short circuit, so the only way to identify the failed board is by unplugging them individually.

        On all Panasonic plasmas that I know, from the back of the TV, the SC is on your left and the SS on your right.

        Originally posted by Falco21
        And yes, I do have a multi-meter. What do you need me to check?
        Can you take some clear photos of inside of your TV? I'll highlight test points and checks to do.

        Any TV saved from landfill is a victory in my opinion. There is far too much waste in this world.
        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

        • Falco21
          Member
          • Jun 2012
          • 10
          • United States

          #5
          Re: Panasonic G20 Failure :/

          Here is one of the entire back:



          Main Power Board (That I replaced):



          A-Board (That I replaced):



          SC Board:

          Last edited by Falco21; 06-06-2012, 02:44 PM.

          Comment

          • tom66
            EVs Rule
            • Apr 2011
            • 32560
            • UK

            #6
            Re: Panasonic G20 Failure :/

            Okay, conventional layout there. In your picture, left is SC, right is SS.

            Try unplugging the SS board (both the main power connector and the little control connector, but not the panel ribbons) and turning the TV on. Does the blink code change? Or does the light go green?

            If not, unplug the TV again, wait 30 seconds, then plug in the SS board, then unplug the SC board (again, all the power and control connectors - but don't unplug the buffer boards going to the panel or any of the panel ribbons.) Power it up again and see if the code changes, or if the light goes green.
            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

            • Falco21
              Member
              • Jun 2012
              • 10
              • United States

              #7
              Re: Panasonic G20 Failure :/

              Unplugged the SS Board and the light now blinks 4 times.

              Plugged the SS Board back in and tried the SC Board. When unplugging the SC Board, it blinks 7 times

              Comment

              • tom66
                EVs Rule
                • Apr 2011
                • 32560
                • UK

                #8
                Re: Panasonic G20 Failure :/

                Originally posted by Falco21
                Unplugged the SS Board and the light now blinks 4 times.

                Plugged the SS Board back in and tried the SC Board. When unplugging the SC Board, it blinks 7 times
                With all control connectors disconnected...? Unexpected on my part...

                Okay get out the meter now. Unplug mains power. Wait 30 seconds. Unplug the SS and SC power (don't worry about control.) Set meter to 200 ohms. Probe between the brown and white power connector wires. Your meter reading should remain unchanged from what it originally showed at 200 ohms for both boards if the boards are 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

                • Falco21
                  Member
                  • Jun 2012
                  • 10
                  • United States

                  #9
                  Re: Panasonic G20 Failure :/

                  Originally posted by tom66
                  With all control connectors disconnected...? Unexpected on my part...

                  Okay get out the meter now. Unplug mains power. Wait 30 seconds. Unplug the SS and SC power (don't worry about control.) Set meter to 200 ohms. Probe between the brown and white power connector wires. Your meter reading should remain unchanged from what it originally showed at 200 ohms for both boards if the boards are okay.
                  I don't understand what you mean by "probe between the brown and white power connector wires".

                  Also, if it means anything, when I tried to connect the power wire to the SC Board, it sparked.

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #10
                    Re: Panasonic G20 Failure :/

                    Originally posted by Falco21
                    I don't understand what you mean by "probe between the brown and white power connector wires".
                    Sorry... I'll be more clear. Make sure red probe is in Volts/Ohm jack and black in the COM jack. On the exposed pins on the SC/SS board, touch the red probe to either side, and the black probe to the other side.

                    Originally posted by Falco21
                    Also, if it means anything, when I tried to connect the power wire to the SC Board, it sparked.
                    This is normal... the capacitors are empty on one board and you charged them up rapidly by connecting them to the P board. Plasma TVs use high voltages (typical "Vsus" is 205V for Panasonic) but 30 seconds are usually sufficient to dissipate these to a safe level. Also, from what I remember, there is a useful safety feature on Panasonic PDPs; a little LED will remain lit on the SC or SS board if there is still a significant stored charge.
                    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

                    • Falco21
                      Member
                      • Jun 2012
                      • 10
                      • United States

                      #11
                      Re: Panasonic G20 Failure :/

                      I sometimes can get a reading, and sometimes it shows nothing. The SC Board showed a few times a reading of 104 then 105. The SS Board showed a few times 198 or so.

                      Comment

                      • tom66
                        EVs Rule
                        • Apr 2011
                        • 32560
                        • UK

                        #12
                        Re: Panasonic G20 Failure :/

                        Originally posted by Falco21
                        I sometimes can get a reading, and sometimes it shows nothing. The SC Board showed a few times a reading of 104 then 105. The SS Board showed a few times 198 or so.
                        Is the reading very brief? That's okay as long as it doesn't stay.
                        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

                        • Falco21
                          Member
                          • Jun 2012
                          • 10
                          • United States

                          #13
                          Re: Panasonic G20 Failure :/

                          Yes it is very brief. Flashes on and off. I tried holding on there, but the reading only shows a few times, not all the time.

                          Comment

                          • Falco21
                            Member
                            • Jun 2012
                            • 10
                            • United States

                            #14
                            Re: Panasonic G20 Failure :/

                            New SC Board is on the way.

                            Seems like the problem

                            Comment

                            • tom66
                              EVs Rule
                              • Apr 2011
                              • 32560
                              • UK

                              #15
                              Re: Panasonic G20 Failure :/

                              Originally posted by Falco21
                              New SC Board is on the way.

                              Seems like the problem
                              If not, it could be SS, SU or SD! I am disappointed that this Panasonic does not tell you which board is at fault. When I repaired a TC-42PZ70BA (old model, but very very well engineered) it would stop flashing the LED if the SC board was unplugged; I used this to quickly isolate that board as being at fault.
                              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

                              • Falco21
                                Member
                                • Jun 2012
                                • 10
                                • United States

                                #16
                                Re: Panasonic G20 Failure :/

                                Well this sucks! LOL

                                Trial and error like I've been doing I guess :/

                                Comment

                                • waitery
                                  Senior Member
                                  • Feb 2011
                                  • 69

                                  #17
                                  Re: Panasonic G20 Failure :/

                                  Originally posted by Falco21
                                  Well this sucks! LOL

                                  Trial and error like I've been doing I guess :/

                                  Falco, did you get the new SC board and did it take care of the issue? Can you let us know? Thanks!!

                                  Comment

                                  • mr.sky
                                    Senior Member
                                    • Sep 2011
                                    • 54

                                    #18
                                    Re: Panasonic G20 Failure :/

                                    Originally posted by tom66
                                    Okay, conventional layout there. In your picture, left is SC, right is SS.

                                    Try unplugging the SS board (both the main power connector and the little control connector, but not the panel ribbons) and turning the TV on. Does the blink code change? Or does the light go green?

                                    If not, unplug the TV again, wait 30 seconds, then plug in the SS board, then unplug the SC board (again, all the power and control connectors - but don't unplug the buffer boards going to the panel or any of the panel ribbons.) Power it up again and see if the code changes, or if the light goes green.
                                    Tom, to your knowledge, do all the Panasonic Plamas have a Green Light
                                    on the SS Board. I too, have the 10blinks, When i turn power on, my SC
                                    board has a Green led that lights up, but not the SS board. Also my
                                    A-Board has a Red light that comes up. Wonder if I have a Bad SS board.

                                    Comment

                                    • tom66
                                      EVs Rule
                                      • Apr 2011
                                      • 32560
                                      • UK

                                      #19
                                      Re: Panasonic G20 Failure :/

                                      Originally posted by mr.sky
                                      Tom, to your knowledge, do all the Panasonic Plamas have a Green Light
                                      on the SS Board. I too, have the 10blinks, When i turn power on, my SC
                                      board has a Green led that lights up, but not the SS board. Also my
                                      A-Board has a Red light that comes up. Wonder if I have a Bad SS board.
                                      I haven't worked on a recent G20 chassis, but on the TH-42PZ80BA both boards have LEDs lit up on them to indicate the presence of high voltage. (Very nice feature from Panasonic so you can't shock yourself.) Look for a place for an LED; is it lit?
                                      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

                                      • mr.sky
                                        Senior Member
                                        • Sep 2011
                                        • 54

                                        #20
                                        Re: Panasonic G20 Failure :/

                                        Originally posted by tom66
                                        I haven't worked on a recent G20 chassis, but on the TH-42PZ80BA both boards have LEDs lit up on them to indicate the presence of high voltage. (Very nice feature from Panasonic so you can't shock yourself.) Look for a place for an LED; is it lit?
                                        On Schematic, it shows Led location on SC board, but it does not
                                        indicate on SS board. On my post concerning TC-42xp14, I have
                                        included link to schematic. I even turned of the lights, and power up
                                        tv, and still do not see any kind of led light coming on SS

                                        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
                                        • 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
                                        • 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
                                        • Biruslapio
                                          Panasonic P50VT20B Plasma 12 Blinks, Power Supply or A-Board?
                                          by Biruslapio
                                          Hello, I've had this TV for 3 years, 2 years ago it stopped working signaling 12 Blinks, SOUND_SOS according to the service manual.

                                          It has no VSUS or VDAT, and P15V has 1.0V instead, the same 15V goes to A board. F15V is ok and other main voltage rails.

                                          It seems the power supply is defective, since unplugging D20 ribbon cable that goes from D-board to SC-board makes the behavior change, the TV stays on, there's no image nor VSUS, but 15V reads 2.4V, high enough to not trip the SOS 12 blinks, so it stays on, fans do not spin but I left it 2 hours, green led lit up...
                                          02-16-2021, 09:44 PM
                                        • Loading...
                                        • No more items.
                                        Working...