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    Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

    Ok so here goes...

    I've searched as much as I can for a similar issue and cant seem to find one. Basically turned the tv on one day and the picture was terrible.

    Firstly, the screen started out black and slowly the picture came through almost like a lava lamp warming up, clearing the screen as it went, which look blotchy almosy as if an pil spill was being taken off. (See Black blotchy pics).

    Secondly, the picture is a complete haze, really dull as if it has a grey cloudy veil in front of it. Its as if someone has drape the tv in an old net curtain and told you to watch the telly through the net curtain.

    Sound is perfect.
    Source is perfect too (sky tv pic perfect on other 42" plasma usomg hdmi, VGA also spot on).

    Done a factory reset in hidden menus. No improvement.
    Run one of those 8hr overnight black/white screen washy things - no improvement.

    I havent opened up the tv yet.... as I like to be heading in the right direction before doing anything with my screwdrivers.
    Ive about read xsus/ysus/tcon/capacitors problems which "might" be the problem, but thought I'd get a major signpost before opening up the telly.

    Any advise/guidance greatly appreciated.
    Cheers Simon

    PS I have a multimeter....and will review the thread on how to use it "again" lol so please treat me as an 8yr when explaining where and what to push/pull/press and where to stick it hahahah

    Pictures to follow....

    #2
    Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

    Without seeing a picture of the problem or seeing pictures of the boards etc. it sounds like a bad z-sus (xsus) board.

    Comment


      #3
      Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

      Sorry for delay, problem uploading from my mobile phone so, reverted tot he laptop. Ok so pics attached, hope they make sense.

      I've included what the picture should look like v's what I have on my broken Plasma- Good Picture v's Bad Picture images.

      You will also see a white image picture, this was a full white screen through the servicing menus, which as you can see is clearly NOT white, its is all grey and cloudy hazy.

      Then you will see the black blotchy lava lamp like pictures, these blotches are only visible when I turn the TV on and as the telly warms up they dissipate, and are fully gone within about a minute or so.

      They what I am left with is the bad pictures, and the Hazy Grey Images.

      Simon
      Attached Files

      Comment


        #4
        Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

        Check and compare the four vital signs voltages with that on the sticker. Vs, Va, Vsc, Ve. are they the same or are they different?

        Comment


          #5
          Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

          Voltage Ratings Update

          Right so I took some readings, under Andrews guidance (cheers) and used the TV Repair Reference Library thread for further assistance on how to do it and adjust the levels as necessary, and these are my findings.

          Voltage - Required Rating (see pic), Actual Reading, Adjusted Reading
          Vs, 205, 178.9, 193.5 (This was max I could get adj screw turned fully).
          Va, 56, 48.9, 53.6 (This was max I could get adj screw turned fully).
          Vsc, -190, -178.8, -190
          (NB I took the reading at the back of the Vscan adj screw (see pic), as couldn't find an output connector - Was this the right way to do it???)

          Ve, 95, I couldn't seem to get a reading on this board at all, so If someone could offer up an idiots guide to where I should hold the multimeter that would be great....
          Please note I did try to copy the way I got the Vsc reading (see pic), but only seemed to get a reading of 0.12, so I'm either doing something wrong or somethings majorly up with this board.

          Anyway after tweeking all other 3 voltages I definitely found an improvement, however not nearly as much as to call the TV fixed. I paused the Sky TV and swapped the HDMI cable between my 42" and the broken 50" and you can see the difference (see pics).

          However for both the, Vs and Va I was unable to adjust the adj screw sufficiently to have the voltages match the Voltage sticker inside the TV.

          Whilst I am not expecting the picture to be as good on the much older 50", but still If it came reasonably close I would be happy. I even went into the picture menus on both TVs and matched the settings (contrast, brightness etc etc) on the 42" so I could be confident the TVs would display as accurately as possible the same image. Moving images are still messy and the colour seems to be way off in the background on peoples faces etc, just not fluid if that makes sense. (Similar to t-con problems other posters describe, and if that's my next steps then please do advise).

          Firstly however, I need to overcome this VE reading problem, as this might suggest this board is the problem.... I'm no specialist see can someone tell me if the board with the VE on it looks okay,? or how to test its voltage? (see pic), also can I confirm this as the Zsus board??

          I have attached a pic of the Control board (please confirm if this is the t-con), just incase any of the eagle eyed gurus in here can spot any anomalies.

          So in essence my next steps are
          1) Find out how to get a reading from VE Voltage?
          2) Confirm is there anyway other ways to adjust Vs and Va to match the Voltage sticker readings?

          As ever all help, guidance and explanations very much appreciated.

          Regards
          Simon
          Attached Files

          Comment


            #6
            Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

            The test point for Ve is on the right side of the board, next to that arrow that's pointing up.

            Also, be careful of the heatsinks, don't assume they are safe to touch, sometimes they are floating at 100's of volts.

            Comment


              #7
              Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

              Cheers Sean,

              Hopefully I'm on the right thing here to test the VE voltage (see pic), I had tried that before - the circular shape to the left of the Upwards pointing arrow with the letters VE just underneath - it did seem like the obvious place lol and then I got all confused when I wasn't getting any reading from it.

              So anyway, this is still giving me nothing? No VE voltage reading. So I'm guessing theres something up with this area of the board?

              Simon
              Attached Files
              Last edited by Simyc1; 05-17-2018, 05:45 PM. Reason: Ooppps forgot to atch the picture

              Comment


                #8
                Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                Quick Update....

                Following on from a distant lack of voltage on the board with VE on it (Zsus??). I decided to check if the actual fuse on it had blown.... (see pic).

                Simple sound beep test on my multimeter confirmed that the fuse was knackered - So off to the shop tomorrow to pick up one of these lil bad boys.

                Will give you an update if that solves the problem.

                Regards
                Simon
                Attached Files

                Comment


                  #9
                  Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                  Before you just replace the fuse, check for a short between ground and the fuse, it is very likely there are shorted components on the zsus board.
                  Also post the board number, It might be LJ41-05307A . there may be some information on what could be wrong with the board. It may be as simple as poor solder connections but more likely shorted fets.
                  Last edited by R_J; 05-17-2018, 07:29 PM.

                  Comment


                    #10
                    Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                    Cheers R J,

                    I'm not 100% I've done this right but I tried to check for a "short between ground and the fuse". Nope, it blew right away!! Either it is too small, and I'll pick up a few 3As to be sure or there is something shorting out the board.

                    The board number is TA515EA188409X, and once I get back from my kids sports day, I'm gonna get on the case of searching the threads for problems with this board too.

                    Onwards and fault finding we go!!!

                    Simon

                    Comment


                      #11
                      Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                      Lets Try again, knew something was wrong when I couldn't find anything online using the barcode number, so reviewed the board again, and with a little help from youtube and shopjimmy -
                      https://www.youtube.com/watch?v=R1jmj_foId0
                      I found the right part number (see pics)
                      PCB No: LJ41-05987A
                      PBA NO: LJ92-01515A/B/C/D/E/F/G
                      PBA Rev: EA1

                      I know the PBA number should only have one letter at the end, but the board didn't have one crossed out to indicate which letter it was and so I refered to shipjimmy and the put forward that the letter should be E = Basically the first letter after a string of 3 numbers in the barcode (see pic)
                      The barcode is TA515EA188409X (the number I incorrectly identified as the part number in my post above).

                      so now I have a PBA No of
                      LJ92-01515E
                      I hope my logic is correct???

                      Simon
                      Attached Files

                      Comment


                        #12
                        Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                        Originally posted by Simyc1 View Post
                        Cheers R J,
                        I'm not 100% I've done this right but I tried to check for a "short between ground and the fuse". Nope, it blew right away!! Either it is too small, and I'll pick up a few 3As to be sure or there is something shorting out the board.

                        RJ meant check for a short to ground by measuring resistance with a multimeter before you place in the new fuse. There's probably transistors on the board that are shorted to ground (causing the fuse to blow). You should only replace the fuse with the same voltage, current and type (Fast, slow etc) as the original.
                        Last edited by sean0118; 05-18-2018, 07:30 AM.

                        Comment


                          #13
                          Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                          There you go . You have a problem with the Z-SUS Bd. To check for the short as requested in the previous posts, with the power off, put your DMM on diode check and connect the Black lead to the chassis and the Red on each terminal of the fuse holder end. If yo get a beep then there is short on the board. Find what is shorting, most likely one ore more of the IGBTs/Transistors. and work to remove that short.

                          Comment


                            #14
                            Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                            For the next hour - Call me the Beep Hunter!!!

                            Comment


                              #15
                              Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                              Originally posted by Andrew F. Ali View Post
                              Find what is shorting, most likely one ore more of the IGBTs/Transistors. and work to remove that short.
                              I'm guessing this is the easier said than done part, and just to idiot proof my approach, Am I doing the same thing again with the multimeter...
                              Connect to ground and touch each IGBT/Transistor/Capacitor...
                              (If it beeps its shorting to ground)
                              and/or
                              Checking across each one of these things (eg Multimeter on one side of a capacitor and then the other? if it doesn't beep its faulty).

                              I swear I must be on the autism spectrum, in terms of needing things spelt out to me. sorry and thank you all at the same time.
                              Simon

                              Comment


                                #16
                                Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                                So far....
                                I've located 2x IGBTs that don't buzz on the multimeter (the other 10 do buzz when testing the middle prong). One on each on the heatsinks... (big silver units??).

                                If these are the source of my problem.... And based on my skill at soldering (or lack of skill lol)... it may well be easier for me to switch out the whole board. I Which is likely to set me back £20-30 quid..

                                If someone could just confirm that this could be the source problem or should I be checking other things first.

                                Cheers Simon

                                Comment


                                  #17
                                  Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                                  That sounds like they are shorted. One or more will have lower resistance then others. But for good measure pull the middle leg on all and mind the.mosfets that are shorted.

                                  Also I read that you turned VA all the way up as I would not do this turn it back down because when you do find the problem VA will Max out and it will certainly destroy your panel
                                  Did I leave the soldering iron on?

                                  Comment


                                    #18
                                    Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                                    Originally posted by freakaftr8 View Post
                                    that sounds like they are shorted. One or more will have lower resistance then others. But for good measure pull the middle leg on all and mind the.mosfets that are shorted.

                                    Also i read that you turned va all the way up as i would not do this turn it back down because when you do find the problem va will max out and it will certainly destroy your panel
                                    +10

                                    Comment


                                      #19
                                      Re: Samsung 50" Plasma PS50A457P1D Grey Blotchy Cloudy

                                      Originally posted by freakaftr8 View Post
                                      That sounds like they are all shorted. But for good measure pull the middle leg on all and mind the.mosfets that are shorted
                                      Defo much handier to just replace the board which if I'm honest saddens me cos I would have loved to get this one going but too many faults.

                                      Anyway Freakaftr8 what do you mean by "pull the middle leg" on the IGBT seeing as I can't mess this board up any worse. I might as well use it as a soldering practice and to learn a bit more.

                                      Oh and don't worry Andrew I'll be sure to turn the Va and VS etc back down before fitting the new board.

                                      Simon

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