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    Samsung SyncMaster 204B White Screen

    Hi,
    today my monitor suddenly went white so I did some searching and found this forum.

    I got this monitor from someone who wanted to throw it away and I was lucky that it only had a few blown caps.
    After replacing them, the monitor worked again (well except the DVI port, the VGA port worked fine).
    Now after about one year using it I got another problem: The screen suddenly went completely white (no flimmering).

    The pictures below are from the Powerboard and the second last picture (or the attached xlsx file) contains some data I took with a multimeter.
    The first table are values for the IC named "IC101" the label says: "f DG13" "B" "DM0565R"
    Found in pictures 13, 14, 26. The numbering if the pins are from bottom left to top left then bottom right to top right as seen in picture 26.

    The diodes can be found in picture 13 and 26 except D104
    D104 is found in 17. Its label says: "JN606" "MBR 20100CT"
    Which as you can see in the data image is not open in the reverse case, but I still have to desolder it to make sure.

    The bridge rectifier D101 can be found in picture 6 and 25

    Fuse F301 can be found in 6 and Fuse F101 in 5 and 21

    After searching this forum a bit, it looks like often a blown fuse is the issue.
    And indeed after testing, the fuse (F1, in the last picture) on the lengthy board is open.

    One question I have is with what should I replace the blown fuse F1?
    There isn't any amps value on the front side and I'm hesitant to lift the board so I can see the backside as there are very thin circuits attached.

    I'm currently planning to replace all the caps (except the big one) and the diode D104 if it is faulty after I desoldered it.
    I don't know about IC101, so I'm hoping you can tell me if it is fine or not with the data I provided.
    If you have anything else I could check or do, I'd be happy to hear it.
    (I still got many pictures of the other two boards so if wanted I can post them too in the next post)
    Attached Files

    #2
    Re: Samsung SyncMaster 204B White Screen

    Correction.
    OK, set the meter in the Ohm mode and check the resistance of top end of the fuse (last picture on the #1 post) against the chassis ground, we need to find out if the load on the output side of the fuse shows low resistance or not.
    Last edited by budm; 08-01-2014, 07:08 PM.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: Samsung SyncMaster 204B White Screen

      I got 2.46k Ohm measured as shown in the attached image.

      Edit: I'm off to bed. I'll be there again in about ~6h.
      Attached Files
      Last edited by Arokh; 08-01-2014, 08:22 PM.

      Comment


        #4
        Re: Samsung SyncMaster 204B White Screen

        OK, the shorts can be after the active circuit that are turned on in the power up sequence. You can use your meter in DC amp mode to check the current draw and see how high the current is.
        Fuse.
        Attached Files
        Last edited by budm; 08-01-2014, 08:50 PM.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment


          #5
          Re: Samsung SyncMaster 204B White Screen

          Sorry, I'm not sure which measurements you exactly want, could you describe in more detail?
          Do you mean I should bridge the blown fuse (F1 visible in image 4 of this post) with the meter in DC amp mode and then take a measurement? Also should I just plug it in or also turn it on for the measurement?

          Thanks for the attachment, now I know which fuse to buy at least.

          (I've also attached the images of the lengthy board from bottom to top)
          Attached Files
          Last edited by Arokh; 08-02-2014, 06:24 AM.

          Comment


            #6
            Re: Samsung SyncMaster 204B White Screen

            I just measured the current with the meter (bridging the fuse F1).
            After plugging it in, it stayed at 0A and after switching it on, I measured 0.75A after a seconds or two.
            I let it run for about 5 seconds before switching it off again.
            The readings didn't jump around but stayed consistently at 0.75A.

            The monitor now displays something random after every switch on (with the meter attached).
            The first time I had a white screen with left and right black borders.
            The second time I had a left white border then in the middle black/white noise and on the right a black border.
            After removing the meter and switching it on I got a completely white screen (without any flimmering) again.

            Comment


              #7
              Re: Samsung SyncMaster 204B White Screen

              OK 0.75A is about right, that is why the fuse is rated at 1.5A. So yo may have other problem with that board, you can use an 1.5A fuse with wires just for testing and see what you get on the screen so you do not have to hold the probes in place.
              Never stop learning
              Basic LCD TV and Monitor troubleshooting guides.
              http://www.badcaps.net/forum/showthr...956#post305956

              Voltage Regulator (LDO) testing:
              http://www.badcaps.net/forum/showthr...999#post300999

              Inverter testing using old CFL:
              http://www.badcaps.net/forum/showthr...er+testing+cfl

              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
              http://s807.photobucket.com/user/budm/library/

              TV Factory reset codes listing:
              http://www.badcaps.net/forum/showthread.php?t=24809

              Comment


                #8
                Re: Samsung SyncMaster 204B White Screen

                Not sure if I should be happy or not:

                I wanted to create a video of the monitor while it is on to show what it is displaying.
                I had to redo the first take which showed a white screen with left and right black bars, because the multimeter display was unreadable.
                After turning on the monitor for the second take (sadly overwriting the first) it actually worked properly.
                Retried it a third type by unplugging waiting 5min and plugging it in again and it was still working.
                Now (while working) the meter displays 0.813A instead of 0.75A and what is a bit odd is that the text now seems to be in Turkish: "Kabloyu Kontrol Et".

                I'll try with a VGA cable attached tomorrow.
                Attached Files
                Last edited by Arokh; 08-02-2014, 05:44 PM.

                Comment


                  #9
                  Re: Samsung SyncMaster 204B White Screen

                  Id be happy with that sounds like a 99% improvement on nothing.
                  Wont take you long to learn Turkish

                  Try something like this - not for your monitor but another samsung
                  Perhaps read German for English.
                  Ok,

                  Note: When I say "press button x times", I am assuming you are starting at the top of each menu.

                  1.) Press Menu (to enter the on-screen Menu).

                  2.) Press Up arrow Twice. This should get you to the setup menu which has the image of a gear next to it.

                  3.) Press 'Enter' button (the one to the left of the Auto button).

                  4.) Press Down arrow Twice (again, assume starting at top).

                  5.) Press 'Enter' (next to Auto)

                  6.) This should bring up a language list (in correct language). Hopefully English is on there. If so, move to it and press 'Enter'.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment


                    #10
                    Re: Samsung SyncMaster 204B White Screen

                    Sadly today I got the white screen with black borders again.
                    So I couldn't try changing the language (and that only works when a video source is attached otherwise the menu won't show up).

                    Anyway here is the video: http://youtu.be/K9-f6aJaKmQ
                    Fast forward 1min to see the issues.

                    First segment was from yesterday (where it worked).
                    Second segment is from today.
                    Third segment is also from today but with lower exposure settings so the colors are more visible.
                    Please note that my camera is not the best and added a blue tint to the video.

                    (I've attached some images from the video linked above)
                    Attached Files
                    Last edited by Arokh; 08-03-2014, 04:00 AM.

                    Comment


                      #11
                      Re: Samsung SyncMaster 204B White Screen

                      I just measured the resistance of my "fuse" (I had to get bit creative, since I don't have a 1.5A fuse yet) and I got ~3ohm.
                      Just to be sure that wasn't one of the problems, I bridged it without any fuse (but still with the meter in the loop) and now I get a proper image again.

                      I'll repeat testing it that way few times more, to be more sure that this is an issue.

                      Comment


                        #12
                        Re: Samsung SyncMaster 204B White Screen

                        I dont recall if voltage has been mentioned but you could use this type of fuse as a temp
                        http://www.ebay.de/itm/Littelfuse-PI...e843d#shpCntId

                        No need to remove the old one but insulate the legs.
                        When yo get a proper one again no need to remove the old one just piggyback the new one - it saves the threat of damage to the board
                        Please upload pictures using attachment function when ask for help on the repair
                        http://www.badcaps.net/forum/showthread.php?t=39740

                        Comment


                          #13
                          Re: Samsung SyncMaster 204B White Screen

                          Yeah, I found out the hard way >_<, I'll remember that the next time.
                          I accidentally also removed a bit of trace. But nothing too serious.

                          I'm currently creating a list at Farnell (I'm also trying to revive my parent's TV by replacing the caps) where they have those fuses:
                          http://de.farnell.com/jsp/search/pro...sp?sku=1596527

                          And the monitor is still working.

                          Comment


                            #14
                            Re: Samsung SyncMaster 204B White Screen

                            Since farnell (private) is a bit expensive I went with reichelt (Pico Fuse).
                            It is not smd but I'll have to be a bit creative anyway since a bit of trace is missing, so that one probably works better.

                            I just now attached a VGA cable to the monitor and worked fine.

                            Anything I should do/check or should I just solder in the fuse and wait until it breaks again?
                            (I'm not sure how high the chances are, that the fuse just blew and everything else is just fine.)

                            Comment


                              #15
                              Re: Samsung SyncMaster 204B White Screen

                              I use lots of PICO fuse for repair, no need to remove the old fuse, just find the pads that you can solder the new fuse in place. Just keep an eye on it, it can be the fuse has weakened.
                              http://s807.photobucket.com/user/bud...tml?sort=3&o=2
                              Never stop learning
                              Basic LCD TV and Monitor troubleshooting guides.
                              http://www.badcaps.net/forum/showthr...956#post305956

                              Voltage Regulator (LDO) testing:
                              http://www.badcaps.net/forum/showthr...999#post300999

                              Inverter testing using old CFL:
                              http://www.badcaps.net/forum/showthr...er+testing+cfl

                              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                              http://s807.photobucket.com/user/budm/library/

                              TV Factory reset codes listing:
                              http://www.badcaps.net/forum/showthread.php?t=24809

                              Comment


                                #16
                                Re: Samsung SyncMaster 204B White Screen

                                Just reporting back. I soldered in the new fuse put the monitor back together and now it is in use again.
                                Lets hope this will hold for some time.

                                Thanks budm and selldoor, you definitely helped me out there!

                                Comment


                                  #17
                                  Re: Samsung SyncMaster 204B White Screen

                                  Well Done!! im deutsche or are you learning Turkish?
                                  Please upload pictures using attachment function when ask for help on the repair
                                  http://www.badcaps.net/forum/showthread.php?t=39740

                                  Comment


                                    #18
                                    Re: Samsung SyncMaster 204B White Screen

                                    Eh, I already forgot. I just tried and is still Turkish.
                                    And... Done. English again

                                    Comment


                                      #19
                                      Re: Samsung SyncMaster 204B White Screen

                                      Thanks for the follow-up.
                                      Never stop learning
                                      Basic LCD TV and Monitor troubleshooting guides.
                                      http://www.badcaps.net/forum/showthr...956#post305956

                                      Voltage Regulator (LDO) testing:
                                      http://www.badcaps.net/forum/showthr...999#post300999

                                      Inverter testing using old CFL:
                                      http://www.badcaps.net/forum/showthr...er+testing+cfl

                                      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                      http://s807.photobucket.com/user/budm/library/

                                      TV Factory reset codes listing:
                                      http://www.badcaps.net/forum/showthread.php?t=24809

                                      Comment


                                        #20
                                        Re: Samsung SyncMaster 204B White Screen

                                        Thank you guys, this thread helped me figure out why all of a sudden I was getting a white screen with my Syncmaster 204B. The problem turned out to be the resistor F1 on the Logicboard. I have also previously done a capacitor replacement fix on the powerboard of this monitor. I am actually surprised that these Samsung Monitors fail like this for after a relatively short period of time, well relative to my ViewSonic PT775, which is made in 1997 and has been in full service without a hiccup since. That's 18 years of trouble free service and still going strong.

                                        Comment

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