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    Re: Samsung Syncmaster 245BW

    Hello all,

    Since a few weeks my screen turns black once in a while. The last few days it happens more often and it won't turn back on.. only sometimes when I wait long enough.

    I've opened the monitor, but I can't see to much wrong at first sight (I'm not an expert in this).

    Is there any chance someone else might know what's wrong or what I can try? I have attached some pictures.

    Thanks so much!
    Attached Files

    Comment


      Re: Samsung Syncmaster 245BW

      "I can't see to much wrong at first sight "

      Have you not read the thread you have posted in???
      Your board is covered in the yellow/brown glue - first step is to remove it
      as it is corrosive and conductive.
      In Picture 2 you have a swollen cap so bearing in mind all the caps are in the same place and the same age it is prudent to change them all except perhaps the BIG Cap.
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

      Comment


        Re: Samsung Syncmaster 245BW

        How do we remove this brown glue? I tried alcohol and it is too hard to remove, very solid.

        Any help is appreciated.

        Thanks

        Comment


          Re: Samsung Syncmaster 245BW

          I have eventually found the time to clean all the glue up and I also now have a multimeter and ordered another 2200uf capacitor to replace the circled capacitor in the picture.

          I have started testing some of the capacitors, the multimeter can only read up to 100uf so the larger caps are harder to test, however the 2200uf is returning 12uf

          I am just curios to know if you have to remove the caps and resistors from the board to get an accurate test or is measuring them from the soldered contacts underneath sufficient?

          My next question is with resistors, can they be partially gone, letting more current than they are designed to do but not completely open.

          Finally, with all the experience in this thread, any ideas what may be wrong? Could it be just the 2200uf cap?
          after replacing the 2 fuses, as stated in above post, the power light comes on and thats it, no picture or stand by mode.
          Last edited by SJones88; 02-06-2014, 04:46 AM.

          Comment


            Re: Samsung Syncmaster 245BW

            Originally posted by SJones88 View Post

            I have started testing some of the capacitors, the multimeter can only read up to 100uf so the larger caps are harder to test, however the 2200uf is returning 12uf
            You can really only test caps with an esr meter and a stand alone cap tester
            and even then you really have to remove the caps. For a one off job or even a few jobs it is not worth the outlay - just replace the caps.
            You have already said the meter only does up to 100uf so pointless testing 2200uf.

            Originally posted by SJones88 View Post
            I am just curios to know if you have to remove the caps and resistors from the board to get an accurate test or is measuring them from the soldered contacts underneath sufficient?
            They are soldered right through the board in little metal tubes (Throughs)

            For resistors it is usually required to unsolder one leg.
            Originally posted by SJones88 View Post
            My next question is with resistors, can they be partially gone, letting more current than they are designed to do but not completely open.
            Normal resistors tend NOT to be a problem if they go they usually show signs.



            Originally posted by SJones88 View Post
            Finally, with all the experience in this thread, any ideas what may be wrong? Could it be just the 2200uf cap?
            Replacing the cap is often just a start point to begin testing -this is not one of the easier boards to troubleshoot

            Originally posted by SJones88 View Post
            after replacing the 2 fuses, as stated in above post, the power light comes on and thats it, no picture or stand by mode.
            I will read back - forgotten the original post Hope you have ordered good quality cap panasonic FR FM or FC

            Did you notice any burn or scorch marks when removing the glue indicating a short?
            Last edited by selldoor; 02-06-2014, 05:25 AM.
            Please upload pictures using attachment function when ask for help on the repair
            http://www.badcaps.net/forum/showthread.php?t=39740

            Comment


              Re: Samsung Syncmaster 245BW

              Thanks for the info, the post I am referring to is from the previous page https://www.badcaps.net/forum/showpo...&postcount=626 the only scorch marks found was the one shown in the picture, the resistors all show some sort of resistance while testing them with BOTH legs still soldered (I was really hoping I wouldn't have to do too much soldering but this doesn't look to be the case)

              the 2 capacitors next to the scorch marks seem fine, the long blue one reads 15nf from the specified 12nf it should be and the ceramic blue is rated at 2.2nf and reads 3.6nf how accurate this is I will leave for you to determine
              "You can really only test caps with an esr meter and a stand alone cap tester"
              however this is the multimeter I am using http://www.uni-trend.com/UT58A.html

              and the 2200nf cap is a panasonic FR, I held off ordering any others as I had no way of testing them until I cleaned the glue off and got a tester (though the cap tester may be useless anyway)

              Comment


                Re: Samsung Syncmaster 245BW

                Ok - I would put off doing anything else to it until the cap is replaced. Reason is it is quite bulged and quite a big one. Put very simply the main purpose of caps is to keep the voltage steady. This voltage is then supplied to other components , perhaps mosfets.
                If the voltage supplied is not clean the mosfets have to work a lot harder, overheat and
                after doing that for some time will breakdown. If they short when they break this has a knock on effect (they are often in pairs and it will take out the other one and possibly more0 and also blow the fuses. So a big soldering job because of one cap.
                You also have to think that if one cap is gone the others are the same age have been in the same environment and whilst may not be working as hard may also be going bad, without any outward signs. So if you get the set going and find soldering is not too bad then think seriously about replacing other caps
                Please upload pictures using attachment function when ask for help on the repair
                http://www.badcaps.net/forum/showthread.php?t=39740

                Comment


                  Re: Samsung Syncmaster 245BW

                  ok, so that large cap came in the post a few hours ago, I have just replaced it, a bit of the metal ring that was on the hole for one of the legs had came away but half of it was still there, my soldering skills arent that great but its now held firmly in place.

                  what would be the next step? plug it in and test it or is it at this point worth while de-soldering resistors and testing them?

                  would testing at this point help to identify the cause? and thus order replacement parts with more capacitors.

                  also what capacitors would you suggest replacing, you said the big one should be ok and testing it showed the capacitance at 80uf-ish out of 82uf (it does have a bit of blackness that looks like it came from the same scorch marks of the picture, this may of been where some hot material had fallen as I did see a spark fall out of the bottom of the screen when it went)

                  one or two of the capacitors do show twice their stated capacitance when tested, this as you said could be related to the inaccuracy of the tester, or could this be a sign that they are going too? as I would of thought, if they where to go that they would get less capacitance.

                  Comment


                    Re: Samsung Syncmaster 245BW

                    Please check you have the cap in the right way round -light stripe on side is negative.
                    if in doubt compare to original picture

                    I would stand well back and plug it in
                    Last edited by selldoor; 02-06-2014, 10:00 AM.
                    Please upload pictures using attachment function when ask for help on the repair
                    http://www.badcaps.net/forum/showthread.php?t=39740

                    Comment


                      Re: Samsung Syncmaster 245BW

                      Originally posted by selldoor View Post
                      "I can't see to much wrong at first sight "

                      Have you not read the thread you have posted in???
                      Your board is covered in the yellow/brown glue - first step is to remove it
                      as it is corrosive and conductive.
                      In Picture 2 you have a swollen cap so bearing in mind all the caps are in the same place and the same age it is prudent to change them all except perhaps the BIG Cap.
                      Hm.. actually it looks quite bad yeh

                      Anyway, thanks for your reply. I will try to clean the yellow/brown glue.
                      I'm still not really sure which caps I should replace, can you name the numbers (see attached picture - and some extras if needed) that need to be replaced?
                      Attached Files

                      Comment


                        Re: Samsung Syncmaster 245BW

                        Badfor Cap no 4 is swollen (same one as SJones88 as it happens) A lot depends on whether you can easily buy good quality caps. Normally recommend for a power supply
                        like this Panasonic FR FM or FC you need to check the physical size and get the same
                        voltage and uf value. If you have to order by post - (perhaps Mouser or digikey or
                        RS components. but perhaps you have a more local dealer. ) then if you jsu buy the one cap the postage will be more than the cap. I would consider replacing 1,3 and 4
                        as a first choice then see how much more it would be for the smaller ones.
                        This is not an easy board to fix so cannot be sure that caps alone will fix it.
                        Please upload pictures using attachment function when ask for help on the repair
                        http://www.badcaps.net/forum/showthread.php?t=39740

                        Comment


                          Re: Samsung Syncmaster 245BW

                          Thanks selldore for the info, true the postage is more expensive per cap however the ebay store I got it from is the only one to sell the rectangular one and none of the local shops sell caps

                          so leaves some of us little choice, as to the replacement cap its on the right way, I read a fair bit of these forum posts over this board and the other board for this monitor (admittedly not all) as far as I can tell there are no other issues so unless replacing the cap shows another fault there shouldn't be any explosions :P saying that your advice is good to keep away but I prefer to remount everything back into the monitor so there is 0% risk of an electric shock.

                          will re-assemble the monitor and will post the results back.

                          Comment


                            Re: Samsung Syncmaster 245BW

                            I have reassembled the monitor and nothing new has changed, plug the power in, turn it on at the switch and press the power button, blue power light comes on and stays on, where standby would kick in after a short while.

                            can turn it on and off with the front button but thats it.

                            Next step to suggest? replace more caps or test transistors with one leg unsoldered?

                            Comment


                              Re: Samsung Syncmaster 245BW

                              Sorry been internetless for a couple of days - changing provider.
                              did you have a pc connected? I think I previously mentioned cpc.com have FREE delivery on all internet orders.
                              "nothing new has changed"
                              Power led staying on is major step forward.
                              Please upload pictures using attachment function when ask for help on the repair
                              http://www.badcaps.net/forum/showthread.php?t=39740

                              Comment


                                Re: Samsung Syncmaster 245BW

                                I did not have a PC connected as the monitor would normally cycle through the digital / analog input then go to standby mode.

                                When I say nothing changed, I was referring to the last test I did before replacing the capacitor, cleaning the glue off, resoldering the small blue capacitor and replacing the 2 internal fuses, the replacement of the 2200uf capacitor made no difference.

                                I will plug in a PC signal and report back.

                                its hard to be internetless, we all seem to depend on it so much nowadays but theres no need to be sorry, your providing free help to random people around the world and on that note would like to say thanks for the help so far!

                                Edit*
                                I have just plugged the screen back in and into a PC, the PC picked up the monitor and its resolution (I gather this means the logic board works) but no change in anything else. power button works, no picture when turned on and a flash light doesnt show a picture either.
                                Last edited by SJones88; 02-08-2014, 06:38 AM.

                                Comment


                                  Re: Samsung Syncmaster 245BW

                                  Ok can you connect it all up and test the voltage on the connector to the main board - use a ground for the negative probe - either a ground screw or
                                  a ground on the connector Post results as follows

                                  Pin1 12v actual 11.56v
                                  PIn2 NC
                                  pin3 GNd
                                  Pin4 5v acctual 5.2v and so on
                                  Please upload pictures using attachment function when ask for help on the repair
                                  http://www.badcaps.net/forum/showthread.php?t=39740

                                  Comment


                                    Re: Samsung Syncmaster 245BW

                                    Badfor: you forgot to say if the image is visible dark with a lamp pointed to the side of screen

                                    SJones: you forgot to say if with pc connected led stays on.

                                    Comment


                                      Re: Samsung Syncmaster 245BW

                                      Thanks selldoor, unfortunately I am going to need a little help on this one, when you say the main board is this the logic board or the inverter board.

                                      If its the logic board there are 2 connectors, is the intention to test all pins on both, further to this the connections to the separate boards have multiple pins for each part (e.g. 3 pins for 5.3v 3 pins for GND etc) shall I test them all, or am I looking in the wrong area?

                                      and I am guessing the ground screws can be any of the 4 corner screws? as I think the screws are easier to use than the ground pins.

                                      Davi.p: the blue power led stays on independent of a connection to a PC.
                                      Last edited by SJones88; 02-09-2014, 02:23 AM.

                                      Comment


                                        Re: Samsung Syncmaster 245BW

                                        Main = logic you can use the 4 corner screws - sometimes the boards are tested all set up but just separated by card and the ground screw isnt grounded so I sometimes suggest using a ground pin. It is easier if you can anchor the black probe somewhere then you just have one probe to worry about.
                                        Pic is connector to start on but all need testing and yes do each pin just in case the NC ones are used - cant always trust what it says on the board.
                                        Attached Files
                                        Please upload pictures using attachment function when ask for help on the repair
                                        http://www.badcaps.net/forum/showthread.php?t=39740

                                        Comment


                                          Re: Samsung Syncmaster 245BW

                                          The screw holes are grounded when around them there is copper or tin.

                                          Comment

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