Aoc n20wb

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • ronhayes
    TV Engineer
    • Mar 2014
    • 458
    • UK

    #41
    Re: Aoc n20wb

    Thank you Vince
    I have tried to re-measure the transformer while it is out and i get nothing like that ?
    In the 2k range i get primary .001 and secondary i get .471 then in the 20k range i get primary 0.00 and secondary i get 0.46
    can you look at this picture am i right with the primary and secondary ?
    Attached Files

    Comment

    • vinceroger69
      Badcaps Legend
      • Mar 2012
      • 6714
      • uk

      #42
      Re: Aoc n20wb

      thats certainly how i would measure them, those readings the ebay seller sent me certainly did sound odd im hoping budm will have a idea im still learning so unsure hence usually wait for budm or a more experienced member to confirm

      Comment

      • ronhayes
        TV Engineer
        • Mar 2014
        • 458
        • UK

        #43
        Re: Aoc n20wb

        Yes my measurements are no where near what they say .
        Hopefully budm can confirm it ?
        Let me know what you want for a ccfl tube if you have a spare one you can let me have.
        Thank you Vince .

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #44
          Re: Aoc n20wb

          At this point I am not convinced that we do not have bad lamp/s because the lamp tester does not have protection circuit, it still light up one lamp without shutting when not all 4 lamps are connected to the tester.
          If it is my board I would use the two test lamps to find out if the board is good or not, that is how I always verify the board when I have 3-second to black problem.
          I really do not know for sure if the secondary winding should be around 500 Ohms or 600 Ohms or not, the primary side will have very very low Ohms.
          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

          • vinceroger69
            Badcaps Legend
            • Mar 2012
            • 6714
            • uk

            #45
            Re: Aoc n20wb

            ron ive posted you two 19in ccfl and two 15in ccfl you should get them tomorrow hope these help with your fault finding on this project and future ones you may even be able too use one of these if you find that ones faulty in this monitor

            Comment

            • ronhayes
              TV Engineer
              • Mar 2014
              • 458
              • UK

              #46
              Re: Aoc n20wb

              Thank you Vince
              After what budm said i thought i would wait until i had a ccfl so i could carry out this test.
              Just let me know if i owe you anything for them?
              Really do appreciate you help.

              Comment

              • vinceroger69
                Badcaps Legend
                • Mar 2012
                • 6714
                • uk

                #47
                Re: Aoc n20wb

                no you owe me nothing, glad i can help you i always keep ccfls tubes out of laptop/monitors and tvs as never know when you may need one for testing/repair,
                and yes i do understand what budms saying now regarding the protection circuit of your tester and thanks again budm for your input into this fault/thread

                Comment

                • ronhayes
                  TV Engineer
                  • Mar 2014
                  • 458
                  • UK

                  #48
                  Re: Aoc n20wb

                  I received the ccfl tubes today from Vince (thank you Vince) i have been to hospital for more tests so could only test the tubes now. there are two tubes running along the top of the screen and two running along the bottom i un-plugged one at a time starting at the bottom of the screen and substituted each one with the ones i received from Vince !
                  It turned out that one of the tubes on the top two was faulty as when i replaced it the back lights stayed on .
                  So i now need to strip the screen down to remove the tubes so i can measure them but it does look like they are 18" . A big thank to (budm and vinceroger69) with out there help i would not have sorted this issue.
                  If any one knows of the best place for me to get replacement ccfl tubes from it would be very helpful.

                  Comment

                  • budm
                    Badcaps Legend
                    • Feb 2010
                    • 40746
                    • USA

                    #49
                    Re: Aoc n20wb

                    Glad to hear and now we also have to pay caution to how the CCFL tester function and its limitation, the company that makes it probably does not provide full details info on how it functions as far as the protection is concerned.
                    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

                    • vinceroger69
                      Badcaps Legend
                      • Mar 2012
                      • 6714
                      • uk

                      #50
                      Re: Aoc n20wb

                      Ron im not sure what size tubes i sent you so dont know if there too long or too short maybe you could use one of the shorter ccfl i sent you and mount it central in the metal bracket? one you have the old tube removed measure the exact tube size i will see what else i have spare, and hope your hospital tests etc come back ok.Ron also check the wiring on both ends of faulty tube as have seen these at fault before and a quick re solder sorted it and be careful with these tubes they break really easily on removal/replacement and aliexpress are the cheapest for the tubes ive found just measure length and how thick the ccfl is.
                      Last edited by vinceroger69; 04-11-2018, 11:57 AM.

                      Comment

                      • vinceroger69
                        Badcaps Legend
                        • Mar 2012
                        • 6714
                        • uk

                        #51
                        Re: Aoc n20wb

                        Originally posted by budm
                        Glad to hear and now we also have to pay caution to how the CCFL tester function and its limitation, the company that makes it probably does not provide full details info on how it functions as far as the protection is concerned.
                        yes like you say its was good too find out this testers limitations as it was hard too tell if the inverter was at fault or not but we have rons readings of the winding ohms that are good for future reference.

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #52
                          Re: Aoc n20wb

                          Test lamps always save me time to narrow down the problem, definitely one of the required test pieces.
                          I have lots of them!
                          https://www.badcaps.net/forum/showth...274#post807274
                          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

                          • vinceroger69
                            Badcaps Legend
                            • Mar 2012
                            • 6714
                            • uk

                            #53
                            Re: Aoc n20wb

                            Originally posted by budm
                            Test lamps always save me time to narrow down the problem, definitely one of the required test pieces.
                            I have lots of them!
                            https://www.badcaps.net/forum/showth...274#post807274
                            Thats a lot of spare lamps budm, certainly be able too save a fair few more monitors etc from the landfill for a few more years and saves buying them as there not cheap new so makes a lot of monitor uneconomical too fix when you have to purchase new parts.

                            Comment

                            • ronhayes
                              TV Engineer
                              • Mar 2014
                              • 458
                              • UK

                              #54
                              Re: Aoc n20wb

                              Vince here are the ccfl tube carrier removed they are 2.4mm tubes and 18" long as seen in the photo . not sure how to remove the end rubber caps without braking the tubes ?
                              The ones you sent me are 14" and 19" but they look the same diameter 2.4mm.
                              Don't worry if you don't have any.
                              They told me that i will have to have more P.E.T.scans after my next lot of chemotherapy as they have seen another mass further down in my stomach and they need to put a camera down to check it out.
                              I have only had one session of chemotherapy so far which was carried out over two days.
                              But so far i am feeling fine but they tell me it will get worse with more chemotherapy.

                              Comment

                              • ronhayes
                                TV Engineer
                                • Mar 2014
                                • 458
                                • UK

                                #55
                                Re: Aoc n20wb

                                Sorry forgot to add these photos.
                                Attached Files

                                Comment

                                • vinceroger69
                                  Badcaps Legend
                                  • Mar 2012
                                  • 6714
                                  • uk

                                  #56
                                  Re: Aoc n20wb

                                  i will have a look when im back at home and see what size i have in my spares is the white end cap rubber im sure i just pull them of the ends i usually cut and double heat shrink the ccfl wires as save trying to solder on too the tube pins as solder dosnt seem to like to stick too them.

                                  Comment

                                  • vinceroger69
                                    Badcaps Legend
                                    • Mar 2012
                                    • 6714
                                    • uk

                                    #57
                                    Re: Aoc n20wb

                                    ron the nearest i have measuring like you are is just under 16.5 i have a pair of these i think came out of a monitor.

                                    Comment

                                    • ronhayes
                                      TV Engineer
                                      • Mar 2014
                                      • 458
                                      • UK

                                      #58
                                      Re: Aoc n20wb

                                      Hi Vince
                                      I was working on the tv today and trying to determine which tube was faulty when i had removed them, So i connected one with one of the ones you sent me it powered up and stayed on so i tried the other one to confirm it was the faulty one but that one powered up as well so i then connected them both up and the backlights powered on and stayed on.
                                      I tried gently tapping and moving the tubes to make sure they stayed on and did not flicker on/off ,they stayed on. So i put all the monitor back together and connected it to my pc for testing it has now been on most of the day with no issues so hopefully it is a fix. (it must have been a doggy connector as you had said it could be.
                                      A very big thank you to you and budm for all your help with this one with out your help i would never had solved it myself.
                                      I have been put on the sick for six months so hopefully i can get more practise on these lcd's and gain much more needed experience.

                                      A big thank you to you and budm for your patience with me thank you.

                                      Comment

                                      • vinceroger69
                                        Badcaps Legend
                                        • Mar 2012
                                        • 6714
                                        • uk

                                        #59
                                        Re: Aoc n20wb

                                        Thats good news i have repaired a couple where the wiring on the end of the ccfl has broke (under that white rubber/plastic bit on the end of the tubes) some times you do see a burn mark,but like you say its working for now and may continue too for a lot longer and yes ron keeping busy the next few months will/may do you good and with this electronics hobby were always learning.

                                        Comment

                                        Related Topics

                                        Collapse

                                        • Superbee_dad
                                          Sharp 80” long short flash backlight error - Help
                                          by Superbee_dad
                                          Hello Sharp TV experts
                                          Our Sharp LC-80LE642U displays one short one long flash error code which is a backlight error. I went into service mode and there were 8 lamp error counts recorded. I reset the count to 0 and did a reset. The last monitor error cause was 16 B00014639:12. 16 is the code for backlight error. I tried to power the tv up but went back into error mode.

                                          > I checked voltages on the power supply board and they all check out .. including 3.28 volts at the error pin.
                                          > There is power to the cpu and T-CONN and no faults found there. The cpu has a flashing...
                                          01-24-2025, 11:51 PM
                                        • ant3202
                                          HP 27es - LED monitor - Monitor Flashing On - Off
                                          by ant3202
                                          Hi Everyone

                                          Lately I am experiencing the deja-vu incident on one of the led monitor like this.
                                          https://www.badcaps.net/forum/troubl...lashing-on-off

                                          The monitor is HP 27es LED Monitor
                                          https://h30434.www3.hp.com/t5/Deskto...e/td-p/6804692

                                          The monitor will randomly blackout and display no signal and will recover again.
                                          Sometimes need to power and off again to restore the display but...
                                          03-20-2025, 07:30 PM
                                        • momaka
                                          Wise Wing F199 19'' LCD monitor - recapped
                                          by momaka
                                          Looking through my repair pictures and notes, it's been a long time since I posted anything in the LCD monitors section. So here goes that.

                                          I'm dedicating this thread to one of the very first LCD monitors I repaired (if not the first one), which was more than 10 years ago now. The monitor is a Wise Wing, model F199. It's a 19” CFL-backlit LCD. I got it for free off of Craigslist in 2009 from a guy, who said he bought it for cheap from Wallmart and the monitor worked only for a little less than 2 years before quitting.

                                          When I saw the Craigslist post, I wasn't...
                                          08-24-2020, 10:58 AM
                                        • sew333
                                          Pc shutdown, monitor flickered with no signal after 10 seconds
                                          by sew333
                                          My pc:
                                          10850K stock 4800mhz stock Kraken X73 good temps
                                          2x16 GB DDR4 GSKILL 3000mhz XMP
                                          Seasonic Tx-850 Ultra Titanium
                                          Gigabyte Rtx 3090 Gaming OC
                                          Aorus Z490 Pro Gaming
                                          1 TB SSD


                                          4 weeks ago i launched Metro Exodus Enhanced and during cinematic advertisement part ( 30 fps ), pc just shutdown.
                                          Also monitor flickered with NO SIGNAL 10 seconds after shutdown. So only monitor and pc was affected.

                                          Next i pressed only power button, rebooted again and its fine again. Happened once and i cant reproduce.


                                          Power...
                                          02-22-2022, 10:27 AM
                                        • triplefour
                                          TCL 75S421 has sound but no backlight not even a flash
                                          by triplefour
                                          TCL 75S421
                                          PSU BOARD: 40-L402H8-PWD1CG
                                          it shows not even a flash of backlight when powering up.
                                          but the tv appeas to turn on and i can hear the sound of the menus moving and clicking. i can power down the tv with the button.
                                          testing the backlights with my tester all 4 strings lit up and showed similar voltage drops. around 110 or so.
                                          unplug mb and leave only psu plugged into backlights (PSU + BL SELF TEST MODE?) does not light the backlights.
                                          i do see 24v but 0v on PSON and BLON (i didnt write this down tho so cant be sure)
                                          with mb connected, PSON...
                                          11-17-2023, 09:54 PM
                                        • Loading...
                                        • No more items.
                                        Working...