Beko/Panasonic Plasma 42B43 problem...

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • scokljat
    Badcaps Veteran
    • May 2012
    • 275
    • Croatia

    #1

    Beko/Panasonic Plasma 42B43 problem...

    Hi!

    Well, after I repaired my LG plasma a friend of mine called me to take a look at his old plasma TV. It's Excello 42B43, a BEKO rebrand with Panasonic plasma module, 2005.

    TV worked fine until recently he moved it to another house. After relocation TV worked for day or two and than died. TV was serviced two times long ago, there are some visible signs of lousy service job on secondary PSU ;-)

    When plugged in TV gets no standby light, no remote or any other button response, but screen has a little background glow.

    There are two PSU's inside. The bigger one on the left side is Panasonic PSU, part of their plasma module, and smaller one on the right side made by Beko (model: Beko-PSU-03).

    After taking it apart I noticed blown fuse on secondary PSU. Secondary PSU (smaller one) made by Beko supplies low voltages to main video I/O board (+5V/+12V, standby, etc...)
    There was visible solder job at left upper corner, two caps, bridge rectifier and one small IC was replaced before. I did some cleaning and resoldering because the big cap at the corner was little bit loose, installed new fuse, plugged it in, relay clicked and after few seconds fuse exploded.

    Now, I found schematics for this particular PSU, poked a little bit with multimeter and ESR meter, can't find anything shorted or bad...

    I believe the problem is on the primary side of PSU. If it's on secondary I doubt fuse should explode like this.

    What do you think?? What plasma module type is it, btw?

    C1031, C1024, D1001 bridge and IC1004 were replaced before. What is IC1004 (FSD200) for?

    Attached schematics is for Beko-PSU-03 (pictures: Beko_42B43_PSU_01.jpg and Beko_42B43_PSU_02.jpg)


    Cheers!

    Suad
    Attached Files
  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #2
    Re: Beko/Panasonic Plasma 42B43 problem...

    I do like Panasonic plasma modules. Very well engineered. They are the best, after Pioneer (but they don't exist any more.) The operation is more or less the same as your LG, although voltages are labelled differently, and no hybrids are used (props to Panasonic for doing it all in discretes.) Screen glow indicates that the PDP is probably still working, including all sustains and PSU.

    Shame then to see with such a nicely engineered PDP, what crappy sub-PSU they put with it !

    I would put in a new fuse, and see if it goes bang. If not, you fixed it. Fuse can blow from wear and tear (lots of turn on cycles, could be worsened by vibration.) If new fuse goes bang, then suspects are the bridge rectifier or power MOSFET. Looks like the bridge has already had a dodgy repair, so I'd try that first.
    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

    • scokljat
      Badcaps Veteran
      • May 2012
      • 275
      • Croatia

      #3
      Re: Beko/Panasonic Plasma 42B43 problem...

      Yes I replaced the fuse after I resoldered possibly loose cap. Relay clicked, and after few seconds fuse blew again. Bridge rectifiers check ok when I test them with multimeter. Also checked all diodes and FET's, nothing is shorted. Well OK, it doesn't have to be shorted to be bad... Did you take a look at the shematics?

      Comment

      • scokljat
        Badcaps Veteran
        • May 2012
        • 275
        • Croatia

        #4
        Re: Beko/Panasonic Plasma 42B43 problem...

        Btw, new fuse literally exploded! My friend and me almost had a heart attack ;-)

        Comment

        • tom66
          EVs Rule
          • Apr 2011
          • 32560
          • UK

          #5
          Re: Beko/Panasonic Plasma 42B43 problem...

          Desolder the bridges and check. There must be a short. If possible, can you feed it from a variable DC power supply, current limited?

          Shattering fuse reminds me of this... https://www.badcaps.net/forum/showpo...26&postcount=5
          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

          • scokljat
            Badcaps Veteran
            • May 2012
            • 275
            • Croatia

            #6
            Re: Beko/Panasonic Plasma 42B43 problem...

            Originally posted by tom66
            Desolder the bridges and check. There must be a short. If possible, can you feed it from a variable DC power supply, current limited?
            I just found a possible problem. There is a serious burn in that corner. This blue cap C1023 looks quite busted. Take look at pics. See this two tiny wires on transformer?! Let's desolder it all out to take a closer look ;-)

            Stay tuned...

            Cheers!

            Suad
            Attached Files

            Comment

            • tom66
              EVs Rule
              • Apr 2011
              • 32560
              • UK

              #7
              Re: Beko/Panasonic Plasma 42B43 problem...

              Yep, looks like the safety cap which should never short under normal conditions (CE requirement)... has 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

              • scokljat
                Badcaps Veteran
                • May 2012
                • 275
                • Croatia

                #8
                Re: Beko/Panasonic Plasma 42B43 problem...

                Originally posted by tom66
                Yep, looks like the safety cap which should never short under normal conditions (CE requirement)... has shorted.
                Wow! Actually cap and diode are OK. They only got dirty when transformer TR1002 burned! These two tiny wires on the transformer primary are disintegrated. My doubt is, is it a cause for malfunction or consequence of some other malfunction on this PSU?!

                What shall I do now? What to put in the place of this transformer, how do I know it's specs??

                Suad
                Attached Files
                Last edited by scokljat; 08-07-2012, 05:05 PM.

                Comment

                • tom66
                  EVs Rule
                  • Apr 2011
                  • 32560
                  • UK

                  #9
                  Re: Beko/Panasonic Plasma 42B43 problem...

                  Th3_uN1Qu3 has detailed the processes for rewinding transformers; you might want to contact him. However, I suspect the failure is due to a shorted MOSFET.

                  You could replace the entire board. You might be able to get a broken screen version of this TV for very little - most go to the dump here.
                  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

                  Related Topics

                  Collapse

                  • jm1234
                    Panasonic plasma TX-P42ST50 - 6 blinks
                    by jm1234
                    Hi,
                    anyone able to provide the service manual for old plasma Panasonic TX-P42ST50E?
                    It turns off almost immediately (0~5 seconds after pressing the on/off button) and starts flashing the red diode 6 times.
                    I disconnected the left-hand side board (SC?, both the ribbon cable and the power cable to it) and also another ribbon going to bottom left board. Then the led signal is 8 flashes. According to service guide to another Panasonic plasma it would mean the left-hand side board is faulty. But I'm not sure it 100% applies to my model.
                    I checked that board for any obvious faults...
                    05-22-2024, 06:59 AM
                  • stecos
                    Panasonic Plasma main board repair (ST30 GT30 VT30 ST50 GT50 VT50),LED with 3 blincks
                    by stecos
                    Hi everyone!
                    I happened several times, in the search for help from the web, to consult this very interesting forum.
                    So I decided to sign up and I intend to participate actively by making available my knowledge and experience on the subject, I'm a new user but at the same time I'm old in the sense that I have 4 decades of experience in repairing and designing electronics but above all I'm a great passionate about the subject.

                    Having said that I come to the gist of my post on the forum as the title suggests.
                    For my passion for technology I'm now collecting several...
                    11-28-2022, 11:39 AM
                  • cloo
                    Panasonic ZT60 plasma tv with strange behavior and 8 blink code
                    by cloo
                    I recently got my hands on a 60" Panasonic P60ZT60 plasma tv (european model) that has some strange issues along with an 8 blink code.
                    It know this tv is getting old but it was once considered one of the best plasmas ever made, and i think it is still holds on to that even by todays standards.


                    So, long story short. When i first got the tv it had a very bright washed out picture with very raised blacks in all picture modes and i couldn't find the cause in the picture setting menus.
                    After doing a factory reset this problem was gone and the picture was back to...
                    01-06-2025, 06:02 AM
                  • Alicat
                    Panasonic Plasma TH-50PZ85U No screen No blinks on red power light
                    by Alicat
                    Hello,

                    Stopped by this site trying to fix my parents Panasonic Plasma TV.

                    Model number is TH-50PZ85U

                    Power comes on and the red power light stays on solid.

                    Did a few checks like hold the power button on for 60 seconds, hold the - Volume while holding the menu button, no luck, still@ blank grey screen as the screen lights up very vague.

                    I also hear a few clicks.

                    I also think my parents said there was a thunderstorm and the TV failed after that.

                    Section 6 in the service manual talks about power and no screen,...
                    10-30-2024, 10:09 AM
                  • Lintesir
                    Panasonic P42S30 Plasma - Pink sparkles
                    by Lintesir
                    My parents' Panasonic P42S30 died recently, and they asked me to have a look at it. I was able to identify the SN-board as the culprit, as it was shorted. After removing Q401, Q402, Q421 and Q422 the short was gone, so I replaced these components and that got the TV working again. However, when testing the tv a bit, I noticed quite bad pinkish sparkles on some colors. For instance the greyish bar on this forum seems to trigger it quite badly. I made a fullscreen test picture with only that color, with the below result.

                    There is about a 5cm high region at the top without any sparkles,...
                    07-26-2024, 03:16 AM
                  • Loading...
                  • No more items.
                  Working...