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Syncmaster 223BW & 2232BW same symptoms different results after repair

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    Syncmaster 223BW & 2232BW same symptoms different results after repair

    Reposting as a new thread after being slapped by "selldoor" for posting on the end of a thread with the same exact issue as mine. Model number differed but the same issue and no one seemed to help the poster "nima158" so lets try again.

    Samsung Syncmaster 223BW & 2232BW both with Production date: July 2007 had the dreaded blinking blue power button light and no signal when connected to a working machine just the dancing input icon. I replaced the C111, 112, 114, 316, & 317 820uF 25V and C113 330uF 25V CapXon caps with Panasonic FM series. Some caps were visibly leaking others were not. I did not replace C107 47uF 50V, C118 2.2uF 50V, or C318 22uF 50V because my experience with motherboards has always been to replace those caps above 47uF. The C118 is located near the panel ribbon connector next to a gob of white glue. C107 is near C118 but under a gob of glue. I have done many motherboards and power supplies over the years as well as some LCDs so I am familiar with careful dis-assembly and board level repair work. Noted caps were replaced (same board for both model 223BW & 2232BW from same production era) and units were reassembled and tested. The 2232BW display was perfect like the first day it was purchased and the owner was happy. The 223BW was not a success or at least once it powered on. The panel displays the signal but has thin washed out vertical lines across the whole screen after a repair that is supposed to fix the common “no display blinking power button” issue. I understand how one screen has this issue while a similar model of the same production batch and same board does not. Just trying to see if there is something else besides the LCD panel ribbon that can cause this issue before I pop the bezel back open. The ribbon on both models was never strained in any way and looks “normal” to me. I was noticing on the 223BW model how the solder joints don't look as nice and flowed from the factory as motherboards or other electronics do to me. Just wondering about cold solder joints causing such odd behavior. I read a posting elsewhere on the net that the use of lead-free solder these days is wreaking havoc because it is not as stable in the high temperatures these components are many times subjected to. And therefore cold solder joints or cracked joints are more prevalent. Any validity to this claim from the Master Moderators that do repairs for a living? I will get my magnifier out and see if I can find anything wrong with the solder joints.

    Please take another look at "nima158's original post about the 216BW with vertical lines. The pics links are still safe and active as I compared them to my new symptom with the 223BW.

    My posted pics show the power and logic boards reflecting before and after recap of the power boards. The pics of the 223BW screen to show the lines I described are shown in contrasting backgrounds and with and without the OSD menu. The mention in other posts of whether the lines pass through the OSD is shown in the OSD closeup to be only on the border of the menu where darker colors exist rather than the center of the menu with it's bright contrasting field. The lines do not pass through the center of the OSD where it is a lighter background color only on the border. Maybe one of the caps I didn't replace like the one near the ribbon connector is bad? The 2232BW didn't have those same three caps replaced and it was perfect after replacing what I described for both in my opening.

    I have always enjoyed learning from this site and helping others on here that have posted to my threads for the last 7-8 years. Thanks again in advance.
    Attached Files

    #2
    Re: Syncmaster 223BW & 2232BW same symptoms different results after repair

    Well I hope I dont stop you enjoying this site but I obviously didnt slap you hard enough.
    I can get books out the library if I want to spend time reading.

    26 people have read (or started to read this and left it.

    Is the 2232BW ok and therefore any reference to it is superfluous
    Please upload pictures using attachment function when ask for help on the repair
    http://www.badcaps.net/forum/showthread.php?t=39740

    Comment


      #3
      Re: Syncmaster 223BW & 2232BW same symptoms different results after repair

      If you've replaced all the suspected caps, then I guess the next step would be to test the voltages coming out of the PSU to make sure that they are back on track.. You seem to have the proper backlighting so the power to the inverter board seems to be right at the very least.. So I'd check the power on the rails going to the video board and make sure they are within spec.

      If you find the voltages are back within spec and still the problem persists, then it may be the case that whatever went wrong on the power board caused other faults down the line --> main board --> t-con --> LCD panel.

      Comment


        #4
        Re: Syncmaster 223BW & 2232BW same symptoms different results after repair

        Got a chance to connect everything in a mock up to take measurements. With power switch off CN2 on power board (connects with cable to display board) has pins marked On/Off & Dim A at either end with three pins from center to one end being grounds and three to the other marked "13.5V". The 13.5V pins each measured 30.9V power switch on or off. The caps I didn't change read as follows:
        C118 (2.2uF 50V) 27.6V with power on or off
        C318 (22uF 50V) reads 0.0V either way
        C107 (47uF 50V) reads 30.3V power on & 29.4V power off

        I do hear a high frequency ringing emanating from the power board when line voltage is applied with the power switch off.

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