Announcement

Collapse
No announcement yet.

Samsung 245BW power led comes on but no backlight

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    #41
    Re: Samsung 245BW power led comes on but no backlight

    Might be a glare in the picture, But on the cap you are testing in the one picture, it looks like you have the red lead on the negative side of the capacitor (Side with the line on it)
    Black should be on that side.

    You did not hurt the cap and I would stick to voltage checks before ripping caps out willy nilly
    Last edited by bammbammfran; 06-03-2014, 07:03 AM.

    Comment


      #42
      Re: Samsung 245BW power led comes on but no backlight

      thanks for all that and yes i am a noob so i could be wrong about a great and many things but of this one thing i am sure: the resistor i was measuring is dead as a doornail. there is no corruption from my fingers (i figured that one out...my resistance is something like 1600k) i replaced that resistor and now i think i may have found the problem in the cm802 cap which is giving me only a 10 nf reading when it should be 18 .. im going to try replacing that first and if that doesnt fix it i will definitely remove and test the other caps.
      Don't fear the repair...

      Comment


        #43
        Re: Samsung 245BW power led comes on but no backlight

        so how do i go about ordering a new one of these?
        Attached Files
        Don't fear the repair...

        Comment


          #44
          Re: Samsung 245BW power led comes on but no backlight

          is this the same thing? http://www.aliexpress.com/item-img/1...143960248.html
          Don't fear the repair...

          Comment


            #45
            Re: Samsung 245BW power led comes on but no backlight

            High Frequency, Switching
            http://www.digikey.com/product-detai...2121-ND/585188
            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


              #46
              Re: Samsung 245BW power led comes on but no backlight

              thanks. ordered it. will let u all know what happens when it gets here
              Don't fear the repair...

              Comment


                #47
                Re: Samsung 245BW power led comes on but no backlight

                Since we're talking about power supplies, electrolytics and reliability, here's an interesting read by Rockwell Automation:

                https://cdn.badcaps-static.com/pdfs/...8bd945dc42.pdf

                "MTBF ratings generally assume perfect manufacturing conditions and proper application of product - key factors that can drastically offset MTBF numbers. A better way to measure the MTBF of power supplies is to take a closer look at the electrolytic capacitors used in the product. Capacitors have a wear-out mechanism, meaning they generally have a limited life, and this can affect the power supply life span."

                Interesting quote in the context that we're posting on "badcaps.net"

                C152Heavy

                Comment


                  #48
                  Re: Samsung 245BW power led comes on but no backlight

                  thanks for all your help so far.
                  the capacitor came in the mail yesterday and i am going to put it in today
                  but then i realized its not like a normal capacitor that has a clearly marked negative and positive side. can i just put it in either way?
                  Don't fear the repair...

                  Comment


                    #49
                    Re: Samsung 245BW power led comes on but no backlight

                    according to what i read, film capacitors and ceramic capacitors are not polarized and can go in either way. so i guess im alright then
                    Don't fear the repair...

                    Comment


                      #50
                      Re: Samsung 245BW power led comes on but no backlight

                      Yes.
                      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


                        #51
                        Re: Samsung 245BW power led comes on but no backlight

                        oh man the 10 dollar soldering iron i bought from ebay http://www.ebay.com/itm/271481357228...%3AMEBIDX%3AIT
                        looks cool and is cheap and actually worked to do the soldering but im afraid it might be too cheap cause as soon as u turn it on, it starts melting itself, and smoke is coming out of the metal part..at the tip and at the base of the tube. what the???
                        i wonder if i should just turn it on outside and "let it burn itself out" ... or maybe ill take it apart and see what exactly is melting... *sigh* ebay....
                        Don't fear the repair...

                        Comment


                          #52
                          Re: Samsung 245BW power led comes on but no backlight

                          oh and what is the alligator clip part for?
                          Don't fear the repair...

                          Comment


                            #53
                            Re: Samsung 245BW power led comes on but no backlight

                            success! it turned out to be that 18nf cap! monitor works fine now! nice! THANK YOU!
                            Attached Files
                            Don't fear the repair...

                            Comment


                              #54
                              Re: Samsung 245BW power led comes on but no backlight

                              dang this is a nice monitor! 1920 x 1200 24 inch!
                              Don't fear the repair...

                              Comment


                                #55
                                Re: Samsung 245BW power led comes on but no backlight

                                just one small complaint though.. i see a faint ghosting effect on some things like 3 super light gray bars coming off to the right of anything with color...like for instance the thumbnail above should appear sharp but the right edge "bleeds" a little creating a kind of shadow of faint bars...
                                you can just barely make it out in the picture i took.
                                if you ignore the vertical lines which are a product of the camera trying to capture something that is refreshing, you can see that the image has a shadow to its right.

                                what could cause this effect, and am i calling it correctly "ghosting" or "shadowing" ?

                                its also happening in various other places of high contrast or certain colors...
                                not life threatening but still not perfect.

                                is this just a LCD screen problem, or could it be something crazy like capacitors almost but just not quite doing their job??
                                Attached Files
                                Don't fear the repair...

                                Comment


                                  #56
                                  Re: Samsung 245BW power led comes on but no backlight

                                  Make sure all the connectors are seated, all the circuit board mounting screws are tight (a lot of boards are grounded through the mounting screws). It can also be bad filter caps on the main/scaler board.
                                  Since you are working a lot now fixing stuff, it may be about time to get Capacitance meter, ESR meter.
                                  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


                                    #57
                                    Re: Samsung 245BW power led comes on but no backlight

                                    yes i have the pieces for the ESR meter and now they gave me the instructions how to put it together so ill try to do that tonight. how necessary is it to get an oscilloscope?
                                    Don't fear the repair...

                                    Comment


                                      #58
                                      Re: Samsung 245BW power led comes on but no backlight

                                      today it seems like the mirroring/ghosting/shadowing effect is getting a little worse...
                                      Don't fear the repair...

                                      Comment


                                        #59
                                        Re: Samsung 245BW power led comes on but no backlight

                                        this is awesome. i bought a kit on ebay for 15 bucks, did a little soldering, and now i have a ESR meter.. well it tests a bunch of stuff...resistors, transistors, capacitance...

                                        http://www.ebay.com/itm/281262386306...%3AMEBIDX%3AIT


                                        so uh.. now i can desolder all the caps from the mainboard and test them! what fun! if only there were another way...
                                        Attached Files
                                        Don't fear the repair...

                                        Comment


                                          #60
                                          Re: Samsung 245BW power led comes on but no backlight

                                          hah good thing i caught myself before doing any of that...it was just a problem with the vga connector on my computer. switched to DVI connection and its all good now!
                                          Don't fear the repair...

                                          Comment

                                          Working...
                                          X