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Hanns-G HG281D, LCD Monitor no power

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    Re: Hanns-G HG281D, LCD Monitor no power

    Great work MicroBell1! Thanks for sharing your success story. Really surprised you were able to use only a 20W soldering iron. That lead free solder can sometimes be a real pain.

    Comment


      Re: Hanns-G HG281D, LCD Monitor no power

      Thanks guys for all your help!

      @retiredcaps... Only 3 or 4 bad traces in 2.5 years? I tied ya in about 15 min in 1 repair.....lol. After the first screwup I did diagram each trace and to which componet it was connected. Came in handy when I screwed up again...hahahaha.

      @momaka... I did use 60/40 so I hope it holds. Came up fine this morning and it's pretty cold here in PA so it should hold the hot/cold cycle ok.

      @jetada123... As did I. I expected it take a tad longer to heat the solder but was suprised how fast it melt. That said the 20watt had trouble (as expected) on a motherboard because of the multi layer board. Doable but a slow process for sure.

      Comment


        Re: Hanns-G HG281D, LCD Monitor no power

        Replaced the Bridge rectifier as suggested by selldoor - it was testing open between the ac negative and the DC negative. the replacement one i got did not, so it seems that was a broken piece. All 8 caps in center section of board replaced now as well. When i put her all back together, still no picture, however, i can plug it in now w/o blowing a fuse and i the power LED light to go from blue to amber. When i attach the monitor to a video card, windows detects it and recognizes its max resolution - so that means some of the logic is alive too. no 12 or 24v power detectable yet, so what pieces should i check next?

        Comment


          Re: Hanns-G HG281D, LCD Monitor no power

          My monitor is just outside of warranty and decided to start flickering both vertically and horizontally. The picture will come on and off several times until the monitor heats up a little then it will stay on and start the jittering/flickering. The picture will sometimes be perfect for a short period after it stops going on and off.

          I've spent some time reading through some of this thread and it seems that bad capacitors are the likely culprit. I have very little electronic experience and my soldering skills are lacking.
          I have a very basic dmm that cannot test capacitance.
          I don't have much light to work with now and I neglected to get photos of what I think is the inverter board for the backlight, so the quality on those are lower. I can get better pictures tomorrow if needed.

          I've uploaded some pictures and resized/cropped. If more detail is needed in an area please let me know.
          Attached Files

          Comment


            Re: Hanns-G HG281D, LCD Monitor no power

            Are you saying the pictures are not your boards?

            Have you tried the monitor on another pc or as external on a laptop
            Please upload pictures using attachment function when ask for help on the repair
            http://www.badcaps.net/forum/showthread.php?t=39740

            Comment


              Re: Hanns-G HG281D, LCD Monitor no power

              Originally posted by selldoor View Post
              Are you saying the pictures are not your boards?

              Have you tried the monitor on another pc or as external on a laptop
              The boards are mine, the lighting wasn't ideal and I'm working with a phone for a camera.

              I've tried it on another PC (it's on another one now). I've been using it as a secondary monitor so I could easily watch it's behavior.

              Comment


                Re: Hanns-G HG281D, LCD Monitor no power

                Can you try setting the PC to the lowest resolution and see if the monitor will work without flickering or going black?
                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


                  Re: Hanns-G HG281D, LCD Monitor no power

                  Originally posted by budm View Post
                  Can you try setting the PC to the lowest resolution and see if the monitor will work without flickering or going black?
                  We know this one well eh bud. He has the symptoms of those small caps on the power board that dry out next to the smitchmode transformer. And those 2 caps on the main board next to the voltage regulators.
                  The 2 on the main board...Photo courtesy of the man above me. Budm
                  http://s807.beta.photobucket.com/use...62664929957295

                  The attached photo shows the caps that need to be replaced on the power supply. The ones circled in red for sure. And you might as well replace the ones circled in blue while your at it. Photo, courtesy of me

                  I read where you mentioned you are not very skilled at soldering. You might want to ask a friend that is. Good luck. ~L-J-7~
                  Attached Files

                  Comment


                    Re: Hanns-G HG281D, LCD Monitor no power

                    Yes, I believe that is what he has.
                    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


                      Re: Hanns-G HG281D, LCD Monitor no power

                      Lumberjack, the board you linked looks a tad different from mine.
                      I'm a little lost as to which caps I should start with on mine. I've got a ton of old parts to practice soldering while I wait on replacement parts to arrive so I'm going to attempt the job myself. Need to learn one way or other.

                      I'm about to put it all back together and try a lower resolution. Should I leave the refresh at 60Hz?

                      Thanks for your help, guys.

                      Comment


                        Re: Hanns-G HG281D, LCD Monitor no power

                        Powered on, perfect picture, changed the resolution to 800x600x60Hz, flickering started immediately. Changed res to 1280x800x60 and 20 minutes in, no problems. Probably just coincidence.

                        Edit: Started back up, doesn't look nearly as bad, but till doing it.
                        Last edited by Crais; 02-12-2013, 06:28 PM.

                        Comment


                          Re: Hanns-G HG281D, LCD Monitor no power

                          You do have bad caps on the main board, that is one of the symptom.
                          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


                            Re: Hanns-G HG281D, LCD Monitor no power

                            Originally posted by Crais View Post
                            Lumberjack, the board you linked looks a tad different from mine.
                            I'm a little lost as to which caps I should start with on mine.
                            I apologize. I didn't even take a closer look at your power board. Looks like they used a different one.

                            Originally posted by budm View Post
                            You do have bad caps on the main board, that is one of the symptom.
                            Yes, I'd replace those 2 on the main board first. That should fix the problem. If you have any problems with the monitor firing up after that, replace the 5 small caps in the middle of the power board.

                            Those 2 on the main board are through hole soldering. It's a little more challenging than when a component is attached to one side of a pcb board. The solder is actually inside the hole. So you might want to practice on a motherboard, or a board with similar solder joints.

                            Comment


                              Re: Hanns-G HG281D, LCD Monitor no power

                              two hours to read this thread from start to finish.

                              i have the same lumberjack issues with my HF289H.

                              i am actually kind of excited to give this a shot (hay..i cant lose) will be filling out the correct description tomorrow with detailed sunny bright pictures.
                              now to go see just what kind of solder iron / multimeter i have laying in the garage

                              Comment


                                Re: Hanns-G HG281D, LCD Monitor no power

                                Hey guys, have been stalking this thread for a bit and finally worked up enough courage to give this repair a shot.

                                The monitor was RMA'd last year for bad capacitors - the standard "won't turn on consistently that escalated into won't turn on at all." Worked fine until a week ago, where it'll stay on for a few seconds, then the picture drops out and the blue light flashes. Out of warranty now.

                                All of the caps look fine (save for maybe the three in the last picture - are those normal?), but I understand that they can be dried out.

                                I don't have an ESR, and could use some help picking out which caps should be replaced on which boards. Should I just replace all of them? Or could it be another issue?

                                Thanks!
                                Attached Files

                                Comment


                                  Re: Hanns-G HG281D, LCD Monitor no power

                                  Originally posted by holbs View Post
                                  two hours to read this thread from start to finish.

                                  i have the same lumberjack issues with my HF289H.

                                  i am actually kind of excited to give this a shot (hay..i cant lose) will be filling out the correct description tomorrow with detailed sunny bright pictures.
                                  now to go see just what kind of solder iron / multimeter i have laying in the garage
                                  Welcome to badcaps! You read the entire thread. Wow, good for you. So you probably have a pretty good idea of what the problem is. Great.
                                  If you have the same board that I have posted before; than the problem is almost always those small caps in the middle of the power board drying out that I had circled. You'd never find anything in my garage. Unless you had a map
                                  Here's the best soldering video I have seen, and was referred to me by retiredcaps. http://www.youtube.com/watch?v=I_NU2ruzyc4
                                  Originally posted by awPhil View Post
                                  Hey guys, have been stalking this thread for a bit and finally worked up enough courage to give this repair a shot.

                                  The monitor was RMA'd last year for bad capacitors - the standard "won't turn on consistently that escalated into won't turn on at all." Worked fine until a week ago, where it'll stay on for a few seconds, then the picture drops out and the blue light flashes. Out of warranty now.

                                  All of the caps look fine (save for maybe the three in the last picture - are those normal?), but I understand that they can be dried out.

                                  I don't have an ESR, and could use some help picking out which caps should be replaced on which boards. Should I just replace all of them? Or could it be another issue?

                                  Thanks!
                                  Welcome to badcaps also! Your board is a little different than the one with the big metal heatsinks that I am used to. But it definitely sounds like it could be the caps. Your board has caps that are easily accessable; so you could replace them all. Or you could start with the 5 smaller ones located all around the center of the board, in case they are dried out; which is common with this model. That'd be a good start. If that doesn't work; we'll need to start diagnostics, and you'll need a good digital multimeter. ~L-J-7~

                                  Comment


                                    Re: Hanns-G HG281D, LCD Monitor no power

                                    awphil, set the PC video resolution to the lowest setting and see if the pictures will stay on, if it does, then the caps by the two LDO regultors need to be replaced for sure beside the caps on the power supply.
                                    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


                                      Re: Hanns-G HG281D, LCD Monitor no power

                                      Originally posted by budm View Post
                                      awphil, set the PC video resolution to the lowest setting and see if the pictures will stay on, if it does, then the caps by the two LDO regultors need to be replaced for sure beside the caps on the power supply.
                                      I hooked everything back up and on the initial power on, before I could adjust resolution, the picture dropped out and the blue light started flashing. I adjusted the resolution to the lowest, but still no picture/wont turn on, just a flashing blue light. Unplugged/replugged cables for a bit to no avail. One thing I noticed was when I had the hdmi cable plugged in, the blue light would completely turn off. As soon as I unplugged the hdmi from the monitor, the blue light would resume flashing.

                                      Left it alone for maybe a half hour, with the power cable in, and finally there was a solid yellow light. Plugged hdmi in, on low-res, and it stayed on for an hour. Then I switched the resolution back up to the highest setting for an hour, but the picture didn't drop again. Tried turning it on/off multiple times, unplugging/replugging power to replicate the problem, but it seems to stay on now. Does it have something to do with it being heated up?

                                      Also, I do have a multimeter, but I have no idea which parts to test.

                                      Comment


                                        Re: Hanns-G HG281D, LCD Monitor no power

                                        That can be due to the ESR of the caps go down when the caps are heated up.
                                        I suspect the C80 and C83 on the main board for the 3.3V and the 1.8V LDO regulator, also can be the caps in the power supply board. You can try the C80, C83 first.
                                        You can use a canned air duster, use it upside down so it becomes cold spray, then you can cool those two caps and see if the picture will go out.
                                        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


                                          Re: Hanns-G HG281D, LCD Monitor no power

                                          Hello, I am new to this forum, but not to replacing bad caps.

                                          My HG281D has been blinking on and off for the last week or so. It only seems to do it when there's a lot of black on the screen. Like on webpages with black backgrounds, and what have you. The power LED stays blue the entire time, so I am thinking it's something to do with the logic board.

                                          Does anyone have a plain text list of the caps that are on the PSU and the logic board? I'm probably going to replace them all.

                                          Comment

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