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Dell 2407WFPb Monitor - Bad Cap

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    Re: Dell 2407WFPb Monitor - Bad Cap

    For the board I am looking at, there is no question that the large cap is gone. One of the legs has rust like material at the junction with the capacitor

    Comment


      Re: Dell 2407WFPb Monitor - Bad Cap

      I think you're in the 1% that needs to replace the large 450V cap. Others have also reported seeing that large cap leaking.

      Comment


        Re: Dell 2407WFPb Monitor - Bad Cap

        I had the same problem with rust on the capacitor.
        When i desoldeer the Cap the leg fel off.
        With the Q651 i had the same problem.
        The best thing you can do is to replace the part from the list
        that mr MPX post.
        I had also an defective bridge rectifier
        By Farnel it only cost you abaut 35 euro

        Comment


          Re: Dell 2407WFPb Monitor - Bad Cap

          Yeah, I have had a look at the components and it "looks" fine - so I am kinda hoping someone will be able to answer my 3 questions

          I want to find out the resistance between the 3 legs of Q651 when it is on the board. I get a very small resistance between the 3 legs (about 115 ohm)

          Also what is the resistance across the Zener diode ZD601 on the board? Again, I get a small resistance.

          Would a 2W rating be sufficient for Resistor R670 (0.23 ohm) - this is the only other component that has obvious damage

          Thanks again

          Comment


            Re: Dell 2407WFPb Monitor - Bad Cap

            I thought I might hijack this thread to ask about my 2407 problem:

            The monitor is completely functional in every way apart from after about 10 seconds from start up it will suddenly flicker from normal to full brightness and stay that way until it is turned off. The brightness setting has no effect once it goes into this full brightness mode.

            I originally changed the inverter to solve a backlight problem as illustrated in this thread:
            https://www.badcaps.net/forum/showthread.php?t=22549

            Now I'm wondering if there is something wrong with my replacement or something else? Any suggestions?

            Thanks

            Comment


              Re: Dell 2407WFPb Monitor - Bad Cap

              Originally posted by sirzur View Post
              Yeah, I have had a look at the components and it "looks" fine - so I am kinda hoping someone will be able to answer my 3 questions

              I want to find out the resistance between the 3 legs of Q651 when it is on the board. I get a very small resistance between the 3 legs (about 115 ohm)

              Also what is the resistance across the Zener diode ZD601 on the board? Again, I get a small resistance.

              Would a 2W rating be sufficient for Resistor R670 (0.23 ohm) - this is the only other component that has obvious damage

              Thanks again
              You need an transistortester to check Q651 and the ZD601
              When you R670 is damage there is more damage.

              Comment


                Re: Dell 2407WFPb Monitor - Bad Cap

                I have a 2407WFPb with what I believe has a bad power supply. I bought a cap kit to try and repair the power board and after further investigation I found some burnt area's on the bottom side of the board. im confortable replacing caps but I think replacing anything else is a little over my head. any feedback would be great .

                http://s34.photobucket.com/user/jaso...ell%202407WFPb

                Comment


                  Re: Dell 2407WFPb Monitor - Bad Cap

                  You only replaced 1 cap in a row? All the caps are the same age same size in the same place - why would you think only one is bad?
                  Anyway on to the chip - it looks burnt but picture is not close enough to tell for sure.
                  If you are sure its gone then you have nothing to lose in trying to replace it?
                  Some mebers just snip the legs or dremmel them then remove the rest of the legs using tweezers - once you only have legs to unsolder it becomes a lot easier.
                  Is there a part number on the chip and also take note which way around it is on the board before you remove it.
                  Some members will not look at pictures hosted off site. you should post them like this
                  We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

                  Please do not post inline and offsite as they slow down the loading of pages.

                  Examples of what is needed

                  https://www.badcaps.net/forum/attach...7&d=1280167246

                  https://www.badcaps.net/forum/attach...6&d=1280167246

                  https://www.badcaps.net/forum/attach...4&d=1280167246
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment


                    Re: Dell 2407WFPb Monitor - Bad Cap

                    Thanks for the reply. that chip , that is chipped does not have any writing or markings on it. I have seen the chip intact in other pictures and it is just black. Going to be hard to find. im almost to the point I would rather just replace the whole power board then to spend time tracking down what cap is bad. I replaced the only 2 that had corrosion on them.. the big 240v and that smaller that looks out of place. I was given this monitor broken for free so all i have invested in it is time and about $10-$15 in caps. Id be willing to sell it cheap if someone wants to take on the project as I dont have the time/know how to troubleshoot boards beyond replacing caps.

                    Comment


                      Re: Dell 2407WFPb Monitor dead psu

                      Can anyone help , I was given a Dell 2407 monitor with a faulty power supply model numer 4H.L2K02.A01
                      The 400v cap was leaking, R670 blown, Q651 (2sk3502) blown and the main fuse has blown.

                      I have replaced the 400V cap, R670, Q651 (2sk3502) and the main fuse, No bang but still no power out.
                      I then replaced the IC651 (L6561D) but still no power out.

                      I have the 300v DC @ L610 TO R605, 166V from R605 to R604 and only 19v from R604 to C614, after that @ T601 no volts.
                      Attached Files

                      Comment


                        Re: Dell 2407WFPb Monitor - Bad Cap

                        Anyone know where to get a replacement or alternate board for the 2407? for under $50.
                        Iv found a few online but they are all over $50 and it just isnt work that much to me.

                        4h.l2k02.a01

                        5E.L2K02.001

                        4H.L2K02.A11


                        https://www.myallparts.com/-p-188.html

                        Comment


                          Re: Dell 2407WFPb Monitor dead psu

                          Originally posted by terry View Post
                          Can anyone help , I was given a Dell 2407 monitor with a faulty power supply model numer 4H.L2K02.A01
                          The 400v cap was leaking, R670 blown, Q651 (2sk3502) blown and the main fuse has blown.

                          I have replaced the 400V cap, R670, Q651 (2sk3502) and the main fuse, No bang but still no power out.
                          I then replaced the IC651 (L6561D) but still no power out.

                          I have the 300v DC @ L610 TO R605, 166V from R605 to R604 and only 19v from R604 to C614, after that @ T601 no volts.
                          Can you post a good clear picture of your power supply board
                          Please upload pictures using attachment function when ask for help on the repair
                          http://www.badcaps.net/forum/showthread.php?t=39740

                          Comment


                            Re: Dell 2407WFPb Monitor - Bad Cap

                            Here are some pictures of the power board, hope they help. The large green cap is fine, the marks are where it was glued the other way up on the power board I removed it from.

                            Terry
                            Attached Files

                            Comment


                              Re: Dell 2407WFPb Monitor - Bad Cap

                              Quick questions - I have to go out
                              The Big cap IS the right way round?
                              There is a small yellow torpedo fuse F701 just to the left of the big cap - does that test ok. Resistance and voltage both sides with respect to ground screw.

                              I think on the Main Board - all these posts and I cant spot a single decent picture of the whole board- near one of the connectors there may be a small black rectangular fuse with a 20 or 2.0
                              on it - if you can find it can you test it as well.
                              Last edited by selldoor; 04-09-2013, 04:58 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: Dell 2407WFPb Monitor - Bad Cap

                                The big cap is the correct way round, I have checked F701 and that's fine. I have had a good look at the board and I can not see any more fuses.

                                I have just uploaded some full size pictures to my website, if you want to have a look at them that would be great. www.linfotech.co.uk/psu1.jpg www.linfotech.co.uk/psu2.jpg

                                Thanks

                                Terry

                                Comment


                                  Re: Dell 2407WFPb Monitor - Bad Cap

                                  Yes the small black fuse maybe is on the Main Board
                                  It was that I was wanting a picture of

                                  On the back of the psu the solder around one of the heatsink joilnts looks a bit odd touching the other trace? (maybe just the picture)- perhaps just try cleaning it up a bit.
                                  Attached Files
                                  Last edited by selldoor; 04-09-2013, 06:02 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: Dell 2407WFPb Monitor - Bad Cap

                                    Here is a picture of the video board the only fuse on it is the white 3A one. this is ok, I know to power board is the problem, if I use a bench test PSU then the monitor works great.
                                    Attached Files

                                    Comment


                                      Re: Dell 2407WFPb Monitor - Bad Cap

                                      Hmm- right - it must be on the board under the metal plate but if you say you can power it up externally then it must be ok SO- back to the psu.
                                      Can you carefully test the volatage across the legs on the Big Cap.
                                      Meter on vdc600.
                                      Maybe also check your mains voltage meter on VAC600
                                      Please upload pictures using attachment function when ask for help on the repair
                                      http://www.badcaps.net/forum/showthread.php?t=39740

                                      Comment


                                        Re: Dell 2407WFPb Monitor - Bad Cap

                                        Yes volts on the main cap correct, I have found out I have no volts on the 200A6 chip (pin 6), or on the transistor that powers chip L6516D (pin 8), but the volts are correct on the 200A6 chip (pin 8). I have 19 volts out of R604 which I think is where the chips get there power. After R604 no power at all.
                                        Attached Files

                                        Comment


                                          Re: Dell 2407WFPb Monitor - Bad Cap

                                          Yes, but how many volts on the main cap?
                                          Please upload pictures using attachment function when ask for help on the repair
                                          http://www.badcaps.net/forum/showthread.php?t=39740

                                          Comment

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