LG 50pc55 Red dots

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • suzi
    New Member
    • Jun 2013
    • 5
    • england

    #1

    LG 50pc55 Red dots

    Hello i have a LG 50PC55,
    When i turn i the set on for the first time in the day i get some red dots in the right top part of the screen, once the set has warmed up the dots go i wanted to get it sorted i was told i need to change the YSUS board which are cheap to get on ebay.
    What i want to know would to solve the problem or do i need to do something else.

    thanks in advance

    Suzi
  • vinceroger69
    Badcaps Legend
    • Mar 2012
    • 6714
    • uk

    #2
    Re: LG 50pc55 Red dots

    maybe a firmware upgrade i am sure tom66 will advise when he sees your post

    Comment

    • suzi
      New Member
      • Jun 2013
      • 5
      • england

      #3
      Re: LG 50pc55 Red dots

      ok thank you for getting back to me so quick.

      suzi

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #4
        Re: LG 50pc55 Red dots

        Maldischarge. Apparently, if the dots go away after some time they are not repairable. (Panel fault)

        There is a repair service offered by another member on this forum:
        https://www.badcaps.net/forum/showth...547#post345547

        but it may not work.
        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

        • capkid
          Badcaps Legend
          • Oct 2010
          • 1339
          • United States

          #5
          Re: LG 50pc55 Red dots

          I fixed a 42" plasma that had a "no picture" issue; the fix included replacing the IPMs under the large heat sinks on both the Y and Z sustains. After the fix, I had red dots (mal-discharge) at the top of the screen only that would dissipate as the TV warmed. Reprogramming the control board did not correct the mal-discharge. This 42" plasma was identical in build to other 42" plasmas I'd fixed in the past; those plasmas had mal-discharge over the entire screen after the Y and Z sus repair, and I was able to reprogram the control boards to eliminate the mal-discharge.

          I'm now working on a 50" LG plasma with a similar panel to yours whose control board cannot be programmed successfully without creating a distorted image, so I had to rely solely on a voltage adjustment. The mal-discharge is mostly on the outer edges of the panel. The voltage adjustments greatly diminished the sparkles, but they were not eliminated:

          - VS on power supply adjusted from 193V down to 185V <-- I'd try gradually adjusting the VS first to see if you get an acceptable image. You may not need to go all the way down to 185V.
          - Vzb on Z-Sustain adjusted from 100V down to 96V <-- may not be necessary if VS adjustment suffices.

          So, the bottom line to all this is that I don't believe your issue can be corrected by replacing components; you most likely have a panel issue.
          Last edited by capkid; 06-11-2013, 11:48 AM.
          LG Plasma Mal-Discharge Correction Service

          Comment

          • capkid
            Badcaps Legend
            • Oct 2010
            • 1339
            • United States

            #6
            Re: LG 50pc55 Red dots

            Sorry, repost.
            LG Plasma Mal-Discharge Correction Service

            Comment

            • vinceroger69
              Badcaps Legend
              • Mar 2012
              • 6714
              • uk

              #7
              Re: LG 50pc55 Red dots

              http://www.plasmafix.com/plasma.php

              Comment

              • capkid
                Badcaps Legend
                • Oct 2010
                • 1339
                • United States

                #8
                Re: LG 50pc55 Red dots

                Originally posted by vinceroger69
                Yep, what's mentioned there is consistent with my thoughts. Coincidentally, the repair shop who produced that site is located in my city. I've bought many parts from them.
                Last edited by capkid; 06-11-2013, 11:55 AM.
                LG Plasma Mal-Discharge Correction Service

                Comment

                • vinceroger69
                  Badcaps Legend
                  • Mar 2012
                  • 6714
                  • uk

                  #9
                  Re: LG 50pc55 Red dots

                  Originally posted by capkid
                  Yep, what's mentioned there is consistent with my thoughts. Coincidentally, the repair shop who produced that site is located in my city. I've bought many parts from them.
                  looks a good site some good tips on it.

                  Comment

                  • capkid
                    Badcaps Legend
                    • Oct 2010
                    • 1339
                    • United States

                    #10
                    Re: LG 50pc55 Red dots

                    Suzi, I'd also look around for some of Tom's posts regarding adjusting voltages if you decide to dive in that deeply and the adjustments I mentioned aren't satisfactory.
                    LG Plasma Mal-Discharge Correction Service

                    Comment

                    • suzi
                      New Member
                      • Jun 2013
                      • 5
                      • england

                      #11
                      Re: LG 50pc55 Red dots

                      Well i have had a look at other posts and it seems like the panel is going based on the red dots going when the TV warms up, So i have been now looking at changing the set for a Samsung PS60F5500 60" which looks a good set.
                      If any other good ones which are at least 55" could be recommended please let me know.

                      Regards

                      Suzi

                      Comment

                      • tom66
                        EVs Rule
                        • Apr 2011
                        • 32560
                        • UK

                        #12
                        Re: LG 50pc55 Red dots

                        Avoid a Samsung in my opinion, poor reliability. Samsung are the least reliable of the big three.
                        LG 60PN6500 or Panasonic TC-P60S60 or Panasonic TC-P55S60 are better models.
                        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

                        • capkid
                          Badcaps Legend
                          • Oct 2010
                          • 1339
                          • United States

                          #13
                          Re: LG 50pc55 Red dots

                          Yeah, I'd get a Panasonic while you can. I'm not sure where I read it (might have on this forum), but Panasonic won't be developing any more plasma panels after this year.
                          Last edited by capkid; 06-11-2013, 07:32 PM.
                          LG Plasma Mal-Discharge Correction Service

                          Comment

                          • tom66
                            EVs Rule
                            • Apr 2011
                            • 32560
                            • UK

                            #14
                            Re: LG 50pc55 Red dots

                            There will probably be 2014 panels, but they will be the same with little to no changes between models. We may see 2015 plasmas if OLED encounters more mass production problems, but OLED is the future...
                            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

                            • suzi
                              New Member
                              • Jun 2013
                              • 5
                              • england

                              #15
                              Re: LG 50pc55 Red dots

                              Hello Tom had a look at the sets and the prices are good just been looking at the Oled sets and at present not cheap maybe prices will come down fast, the set i was looking was also a smart TV which seems the way forward and wanted one good for my son to play his consoles on.

                              Suzi

                              Comment

                              • tom66
                                EVs Rule
                                • Apr 2011
                                • 32560
                                • UK

                                #16
                                Re: LG 50pc55 Red dots

                                You won't really miss smart features (nothing special) but if you want smart features:

                                Panasonic TC-P60ST60
                                Panasonic TC-P55ST60
                                LG 60PH660V
                                LG 60PH670V

                                are the ones to go for.

                                Again I strongly recommend NOT buying any product made by Samsung. They are very poorly made and have high failure rates, almost double LG and Panasonic's.
                                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

                                • legg
                                  LG 42PC3 buffer output doesn't follow YSUS
                                  by legg
                                  LG42PC3D -UD originally with green lamp but no display or audio.
                                  Owner says was working, then went 'pop'.
                                  All 5V caps bulging. replaced.
                                  All PSU output voltages within spec but -Vy is low on YSUS.
                                  One of three parallel fets between SUS_OUT and SUS_DN is zenering,
                                  eventually shorts DG. Replaced all 3 - -Vy now OK.

                                  Y scan buffer test point does not follow YSUS output below -50V

                                  Note: This unit seems to expect YSUS output to park at -Vy in between
                                  drive signal pattern periods. A replacement drive signal board confirms this....
                                  11-18-2021, 11:49 AM
                                • Truncatedhose
                                  Help repair this relic? Philips 42PF7220A/37, pulsing buzz from YSUS
                                  by Truncatedhose
                                  Greetings all!

                                  Originally this set had the usual messed up video symptoms such as: horizontal lines, weak, grainy video, bottom and top of picture differ in intensity of problem. It also seemed to slow to turn on or show the messed up picture.

                                  Seemed like must be YScan/buffer board failure. Ordered buffer boards from my distributor which were supposed to be original/new and also from another distributor, I ordered the YSUS because I wanted to replace it for preventative maintenance. (also, the YSUS had a bulged cap, so there was even more reason to suspect it could...
                                  07-04-2018, 10:59 AM
                                • zwarder
                                  eax61319402 50PJ350 YSUS
                                  by zwarder
                                  Hi
                                  Had shorted YSUS

                                  Q24 RPJ63F3
                                  C726 cap
                                  Q11 K3667
                                  R528 & R529 2.2 ohm

                                  replaced all of these but still trips psu VS & VA are a bit low when ysus disconnected. IC301 does look a bit burnt however

                                  ZSUS is also good as far as I can tell

                                  Anyone could help me out on this one
                                  10-23-2023, 08:11 AM
                                • r-p
                                  Maldischarge-link that fixes it with replacing caps
                                  by r-p
                                  Starting this thread because Capkid doesn't seem to be reprogramming controlboards anymore (LG 60PZ950 with red maldischarge) and my game-plasma also has maldischarge (Hitachi 42PD3200). So I will grasp at straws to keep them running. I am extremely bad at throwing stuff away.

                                  Is there any merit to this link?

                                  Very short version: Specific caps seem to loose their capacitance and/or increase their ESR. This may cause the maldischarge. Replace them with better/bigger/newer ones and problem solved.

                                  From the limited knowledge I have on the subject, I think...
                                  01-21-2020, 05:16 PM
                                • motanya
                                  HP 820 G3 Dots/Blurry Screen
                                  by motanya
                                  Hp 820 G3
                                  6050A2725001-MB-A01
                                  This laptop has dots that show up once on the windows login screen. The bios menu and windows loading phase doesn't have them.

                                  What I have tried:
                                  change screens but it's not a screen issue as they show on internal and external display.
                                  Changed SSD and Windows
                                  Wrote a new bios
                                  Inspected if there is anything unusual on the board, none

                                  Has someone seen this before, what could be the issue...
                                  03-21-2025, 11:32 AM
                                • Loading...
                                • No more items.
                                Working...