Panasonic P42S30 Plasma - Pink sparkles

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Lintesir
    New Member
    • Jul 2024
    • 5
    • Netherlands

    #1

    Panasonic P42S30 Plasma - Pink sparkles

    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.
    Click image for larger version  Name:	PXL_20240725_181605673.MP.jpg Views:	0 Size:	868.4 KB ID:	3316613
    There is about a 5cm high region at the top without any sparkles, immediately below that it is the worst and then it fades out towards the bottom. I don't really know if this was already present before the repair, because it's not my tv and with normal content it is not super noticable (and my parents' eyesight is not the best anymore). The image retention also seems quite bad, but I haven't had a plasma for a while, so I don't know if it is normal. Finally, there is a test pattern in the service menu that is listed as 'LOW STEP WHITE' which is just black with a lot of red and green sparkles on this tv.

    I read on this forum that this might be Vsus related, so I measured it and it was 211V. The service manual said it should be 215V, so I turned the Vsus pot until it was at 215V, but that did not make a noticable difference. I also set Vsus to high in the service menu, also without result (apart from the brightness increasing a bit). I then tried to see if any normal settings would make any difference, and found out that setting the Intelligent Frame Creation to Max, the sparkles were reduced a lot! I could just leave it at that, but I would rather have an actual fix for this. Any ideas what might cause this?
  • Lintesir
    New Member
    • Jul 2024
    • 5
    • Netherlands

    #2
    Oh yeah, I also tightened all screws and reflowed the solder on the screw holes on the top and bottom.

    Comment

    • Biruslapio
      Badcaps Veteran
      • Nov 2013
      • 552
      • Brasil

      #3
      Sustain problem, there's something still damaged on the sc/sn board, maybe a resistor or diode damaged after the current surge, or fake IGBTs.

      Comment

      • R_J
        Badcaps Legend
        • Jun 2012
        • 9515
        • Canada

        #4
        If the old mosfets, drain, source shorted to gate then the drive circuit is likely bad, check the resistors in the gate circuit of the mosfets, if the resistors are bad the drive ic's are likely bad, if the resistors are ok, the drive ic's could still be bad and not driving the mosfets
        Last edited by R_J; 07-26-2024, 05:24 PM.

        Comment

        • Lintesir
          New Member
          • Jul 2024
          • 5
          • Netherlands

          #5
          Originally posted by Biruslapio
          Sustain problem, there's something still damaged on the sc/sn board, maybe a resistor or diode damaged after the current surge, or fake IGBTs.
          I suspected it might have been fake IGBTs, they looked a bit suspect. When looking for different ones, I found that a replacement board was not that much more expensive (less than €30 on Ali), so I went for that. The first one was a DOA (got my money back), so I ordered another one that worked like a charm. I was quite surprised how many of these boards are offered there, there must have been at least 30 different sellers.

          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
          • 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
          • badcappo
            Dead Panasonic Viera TX-P65STW50 Plasma TV
            by badcappo
            Hello, got a ST50 plasma TV for repair. No signs of life, not even blink codes. Opened it up to check the power supply, type MPF6914. Apparent issues from visual detection and measuring for shorts:
            Diode type G972s6 - D101 with a short
            Mosfet 06N90E - Q301 shorted
            Fuse T5AH 250V - F103 blown
            Diode D301 shorted
            Relay DG1U-17VDC II - RL001 blown

            I have not found a circuit diagram. Maybe someone here already dealt with a similar issue? Thanks for tips where else to check 😀...
            11-24-2024, 11:27 AM
          • tofik
            PANASONIC TX-P42X10Y Plasma TV damaged after a power spike
            by tofik
            Hello, I have an PANASONIC TX-P42X10Y Plasma TV, purchased new in 2009.
            Unfortunately plasma is not working at all after a power spike. Standby LED is not even working.

            I did some quick tests, YSUS + ZSUS MOSFETS and IGBT's are free from shorts, diodes on these modules seems to also be fine, buffer board is free from shorts as well.

            Anyway I focused mainly on the PSU, did some voltage tests with the results as below, I attached them on the photo (also please see attached PDF with the SERVICE MANUAL for this model, page number 43).

            I understand...
            02-17-2023, 02:34 PM
          • Loading...
          • No more items.
          Working...