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Panasonic plasma TH-42PZ80U 2 blink 15v SOS

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    Panasonic plasma TH-42PZ80U 2 blink 15v SOS

    Power supply part number ETX2MM702MF. Pickings are slim, pretty much every store I've looked at online once had them but is now out of stock. I have heard that these power supply boards are plagued with bad caps, but at least visually everything appears to be fine. Most are Nippon with a few Panasonics.

    I'd like to get a pic of the back of the board but almost all the switching transistors are mounted to a metal back plate that works as a heat sink.

    The error code given by the CPU is 15v SOS. I followed the basic troubleshooting steps that I found online which was basically to test pin 1 of the P7 connector for 15 VDC, which I did not get consistently. Sometimes not at all and sometimes only 1.5 V. From there the troubleshooting manual said replace the P board but nobody really has them. The D board is also possible, but only if the P board was actually generating 15 V and it was simply being incorrectly marked as outside tolerances for voltage or current. I'd like to test the PS without the 15V connection to any other boards to see if the PS is actually generating it, but if I unplug P7 the PS does not fire up as it has to be commanded by the D board. Other possibilities are any board with 15v is shorted or bad. (Pin 1 of P7 to ground measures 1500 Ohms on PS) Any ideas where to go from here? Startup sequence when the plug is initially plugged into the wall appears to complete without a problem, it's just when the set is turned on that it goes into SOS mode. I will try to get better and more pictures, but no obvious signs of heat damage or bulging caps anywhere.

    TIA!

    Chris
    Attached Files

    #2
    Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

    Somewhere (Scribd?) I saw a Panasonic training manual that described troubleshooting their TV power supplies. The relevant part for your problem described taking two AA batteries in series and WITH THE POWER SUPPLY DISCONNECTED FROM THE MAIN BOARD, forcing PSON (or whatever the control input is called) high, then checking the outputs.

    PlainBill
    For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

    Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

    Comment


      #3
      Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

      Sounds like it's worth a try, I'll do some more poking around. From your bolded statement I'm going to assume that it would be bad if I were to follow through with my plan to remove the 15v+ line from the P7 connector on the power supply and measure the unloaded 15v+ line at the PS without disconnecting any other cables?

      Comment


        #4
        Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

        Originally posted by BarrelRoll View Post
        Sounds like it's worth a try, I'll do some more poking around. From your bolded statement I'm going to assume that it would be bad if I were to follow through with my plan to remove the 15v+ line from the P7 connector on the power supply and measure the unloaded 15v+ line at the PS without disconnecting any other cables?
        I'm unable to predict this. The sets I have the most experience on (Philips) monitor the voltages ad shut down the power supply if one doesn't come up. This occurs within a second or two, scarcely enough time for a human to get a voltage reading. I would say that a GOOD design would tolerate a missing voltage without any damage. But I don't know if the designer would agree with me....

        I'd suggest disconnecting the supply from the main board and forcing it on. Use a small automotive light (1157 tail light) to provide a load.

        PlainBill
        For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

        Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

        Comment


          #5
          Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

          Hi, did you find a fix for this?? I have the same tv with a no power issue

          Comment


            #6
            Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

            same problem here... replace the A board and D board and still have the problem... i dont wanna pay 150 for a power board... im sure they are always the same caps and resistances that get burned. but i dont know whichones

            any ideas? have anyone solved this problem?
            thanks
            alex

            Comment


              #7
              Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

              Originally posted by creativeguitar View Post
              same problem here... replace the A board and D board and still have the problem... i dont wanna pay 150 for a power board... im sure they are always the same caps and resistances that get burned. but i dont know whichones

              any ideas? have anyone solved this problem?
              thanks
              alex

              If you turn on your set with all the boards in it and your fans do not kick over (start and then stop momentairily) with a 10 blink code, the likelihood is that the power supply is the cause. If I were you, I would stop buying boards and either repair the power supply or bite the bullet and replace it with a new/used functioning unit.

              Comment


                #8
                Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                Originally posted by BarrelRoll View Post

                The error code given by the CPU is 15v SOS. I followed the basic troubleshooting steps that I found online which was basically to test pin 1 of the P7 connector for 15 VDC, which I did not get consistently. Sometimes not at all and sometimes only 1.5 V. From there the troubleshooting manual said replace the P board but nobody really has them. The D board is also possible, but only if the P board was actually generating 15 V and it was simply being incorrectly marked as outside tolerances for voltage or current. I'd like to test the PS without the 15V connection to any other boards to see if the PS is actually generating it, but if I unplug P7 the PS does not fire up as it has to be commanded by the D board. Other possibilities are any board with 15v is shorted or bad. (Pin 1 of P7 to ground measures 1500 Ohms on PS) Any ideas where to go from here? Startup sequence when the plug is initially plugged into the wall appears to complete without a problem, it's just when the set is turned on that it goes into SOS mode. I will try to get better and more pictures, but no obvious signs of heat damage or bulging caps anywhere.

                TIA!

                Chris
                I have the exact same problem on a th46pz80.
                Any one has a fix on these yet?
                Or any one has the service manual to trouble shoot?

                Comment


                  #9
                  Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                  Originally posted by BarrelRoll
                  <snip>I have heard that these power supply boards are plagued with bad caps<snip>
                  Horsecrap. Don't believe it for a second.

                  The reason is your next statement-
                  Originally posted by BarrelRoll
                  Most are Nippon with a few Panasonics.
                  Originally posted by BarrelRoll
                  <snip>Other possibilities are any board with 15v is shorted or bad. <snip>
                  Not just -any-, but one in particular. You need to supply some voltage to the 15v inputs on the other boards to see which is drawing a lot of power. A 9v battery with an 1157 bulb in series like PlainBill said will show what's drawing the most. An ohmmeter check (analog please, DMM's numbers jump around too much) will likely show low resistance between ground and the 15v input on the suspect board. Find what boards need/use the 15v and go from there.

                  Originally posted by BarrelRoll
                  <snip>(Pin 1 of P7 to ground measures 1500 Ohms on PS)<snip>
                  Is that with the plug (P7) disconnected from the board? Plug it back in and see what the reading is then. Probes both ways with meters as diodes in the lines can give you a false reading.

                  Did this occur after a storm that would have had a nearby lightning strike or power surge?

                  Toast
                  veritas odium parit

                  Comment


                    #10
                    Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                    Originally posted by fastvideo View Post
                    I have the exact same problem on a th46pz80.
                    Any one has a fix on these yet?
                    Or any one has the service manual to trouble shoot?
                    A defective D board found.

                    Comment


                      #11
                      Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                      Originally posted by BarrelRoll View Post
                      Power supply part number ETX2MM702MF. Pickings are slim, pretty much every store I've looked at online once had them but is now out of stock. I have heard that these power supply boards are plagued with bad caps, but at least visually everything appears to be fine. Most are Nippon with a few Panasonics.

                      I'd like to get a pic of the back of the board but almost all the switching transistors are mounted to a metal back plate that works as a heat sink.

                      The error code given by the CPU is 15v SOS. I followed the basic troubleshooting steps that I found online which was basically to test pin 1 of the P7 connector for 15 VDC, which I did not get consistently. Sometimes not at all and sometimes only 1.5 V. From there the troubleshooting manual said replace the P board but nobody really has them. The D board is also possible, but only if the P board was actually generating 15 V and it was simply being incorrectly marked as outside tolerances for voltage or current. I'd like to test the PS without the 15V connection to any other boards to see if the PS is actually generating it, but if I unplug P7 the PS does not fire up as it has to be commanded by the D board. Other possibilities are any board with 15v is shorted or bad. (Pin 1 of P7 to ground measures 1500 Ohms on PS) Any ideas where to go from here? Startup sequence when the plug is initially plugged into the wall appears to complete without a problem, it's just when the set is turned on that it goes into SOS mode. I will try to get better and more pictures, but no obvious signs of heat damage or bulging caps anywhere.

                      TIA!

                      Chris
                      I just got through fixing a 50'' plasma and it seems to be alot like the 42.If its the same set up you can unplug A5 from the A board and then when you plug it in the wall you should get a white screen without even pressing the power button,mine did not so the A board was bad couldn't find one anywhere,I sent it to be repaired by moduslinktv,may have to put in search for right address,but that fixed my problem think they charged about $130

                      Comment


                        #12
                        Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                        If the fans don't spin for a second when you power on you need to repair or replace mc201 and mc301.

                        Comment


                          #13
                          Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                          They aren't cheap but 99 times out of a hundred its mc301

                          Comment


                            #14
                            Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                            HERE IS THE FIX!

                            You must replace the IC's and 1uF capacitor on a couple different boards. There are what we call "IC packs" that regulate voltage for the A board and SC/SS boards. They stick up out of the PSU on green PCB's ... the labels are MC201 and MC301.

                            Here is a great video tutorial for the 704 board, but it still applies to yours.

                            Comment


                              #15
                              Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                              G'day

                              I have replaced the IC's & 1uF caps on MC201 & MC301, it worked for 3 days without any problem, but suddenly it shut down and standby LED started with 2 blinks again. Anything else to look for, any help will be appreciated.

                              Comment


                                #16
                                Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                                Are you sure the ics and caps are making a solid connection? Also what kind of cap did you use?
                                Did I leave the soldering iron on?

                                Comment


                                  #17
                                  Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                                  Thank you freakaftr8 for your quick reply, all soldering are solid hard, also the caps bought from a supplier here in Sydney Australia (SMD 1uF/50v).

                                  cheers
                                  kendo

                                  Comment


                                    #18
                                    Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                                    the only thing I can think of is possibly the 1mfd smd capacitors you purchased or one of the ics are unstable. Try swapping the caps temporarily with 1mfd electrolytic I beleve ground faces up. Double check google pics first.
                                    Did I leave the soldering iron on?

                                    Comment


                                      #19
                                      Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                                      Thanks again freakafter8, I found 2 FETs (16N55) both short cct, and blown 5A fuse.
                                      replaced the faulty components. Now when I plug the power in the relay click but I have 10 blinks and missing 15v on plug6/pin7 even plug6 removed from socket still no 15v.

                                      cheers
                                      kendo

                                      Comment


                                        #20
                                        Re: Panasonic plasma TH-42PZ80U 2 blink 15v SOS

                                        Could be cap on MC201/MC301. Can fail causing this -- recommend replacement at same time as replacing for 2 blink.
                                        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

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