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Dell 2407WFPb Monitor - Bad Cap

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    Re: Dell 2407WFPb Monitor - Bad Cap

    Hi Guys,

    Over a year ago my Dell 2407 WFP monitor went pop, opened it up and same deal as everyone else, the big main cap was dead along with the big pink resistor, and who knows what else?

    I put off repairing the burnt/faulty parts as I have a second Dell 2407 WFP which I was happy to use... Until the other day this one also went, pop!

    Opened it up and sure enough, same parts were dead.

    Looking on eBay and the internet, the entire power board is available for purchase 4H.L2K02.A01 which would make things much easier, rather than sourcing and troubleshooting many replacement components, not to mention the hours involved!

    So I am going to order 2x replacement power boards as they are pretty cheap. I will report back on my success to let others know if all went well!!

    Comment


      Re: Dell 2407WFPb Monitor - Bad Cap

      Board replacement is not really what we are about, unless there is no alternative.
      Perhaps update your profile with country and mains voltage. These boards may not be available
      in all countries.
      Last edited by selldoor; 08-16-2014, 04:35 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

        Originally posted by selldoor View Post
        These boards may not be available
        in all countries.
        They are mostly available in the US and CHINA, one thing I have overlooked is the compatibility with a countries AC power. Any ideas how to verify if the power board I am purchasing will be compatible with AU (Australian) Power mains at ~230-240v 50Hz?

        How does one verify this, there is no explanation in the eBay listings. I guess my question is are these monitors using a universal power board that is identical in all models sold in every country, and will a replacement board work with any countries voltage?

        EDIT: OK, I found the following specification from -
        100 to 240 VAC / 50 or 60 Hz +3 Hz / 2.0A (Max.)

        So with that I would assume the power board is auto switching and there is only one type of power board manufactured which is universal and will work with every countries voltage line...
        Last edited by dom03; 08-17-2014, 08:37 PM.

        Comment


          Re: Dell 2407WFPb Monitor - Bad Cap

          sounds like it.
          but you really should fix the originals - you have no idea how long the replacements will last.

          atleast get one replacement to get you running,
          then fix the faulty pair - then you have a spare for next time.

          Comment


            Re: Dell 2407WFPb Monitor - Bad Cap

            Hello electronics experts,

            I've got classic 2 seconds to black problem with my Dell 2407WFPb: on turning on, it goes black after a very brief display of whatever supposed to be on the screen; power button stays green.

            There's no audible hiss or buzz, PSU and inverter boards look absolutely fine - no blown caps, no leaks, nothing visibly wrong but one thing: the tin cover that goes over inverter board has six rusty spots inside, just where the lamps are plugged in. Not sure if it's relevant -- photo attached.



            I've read the troubleshooting guide and trying to make use of it.

            Tried turning it on with only one lamp connected, each appeared to be working - at least they fired up all right before going to black. Can't be sure if they all were equally bright though.

            Inverter fuses are OK. Hasn't tested much else.

            I've replaced all the caps on both inverter and PSU boards (except the big 120uF/450v one) with Panasonic FMs; nothing has changed.

            I'm going to properly test transistors, diodes and transformers later on, but first I'm going to grab the same model (working) monitor from work and try exchanging boards around to see which part is faulty. Yes I do realise I should have done that first, but it's a bit of a pain and can only be done on a weekend.

            In the meantime, I'd appreciate an advice on following:

            - Is it still a good idea to order and replace the 120uF/450v cap?
            - Is it a great idea to order another handful of caps to replace them in the (currently) working monitor at work, just for the sake of it?
            - Do I still have to properly check inverter/lamps with a test CFL(s)?
            - Am I missing anything obvious?

            Thanks
            Attached Files

            Comment


              Re: Dell 2407WFPb Monitor - Bad Cap

              Gave it another try, even though the speaker-output modification works just fine (on 4.5A 20V laptop powersupply).

              The data I provided last time (2 years ago?) was it drew 3.2A at 19 or 20V, but my switch mode powersupply had a broken cap.
              Now it shows 3.8A consistently at 20.0V, so I am hoping the 4.5A PS is just fine. I couldn't get that 3.8A value to increase with video compared to just the desktop (only to less when the screen was black).

              But when I saw this chip (see pic, the PCF chip), and read the board really does nothing else than make 19V and I couldn't recall where I left the output inductor (that you remove for the speaker-output-mod), I gave up.

              I have a tendency to cause a second fault when fixing the first...



              (Just 2 weeks ago I broke off a (heavily corroded) groundwire in father-in-laws car when trying to find a solution for a fuse blowing. It eventually took me over 20 hours (chasing red herrings and feeling very guilty) to find both errors (the other was a rubbing wire, causing a short from sparkpluglead to chassis) and realising the ground would have broken off anyway within weeks. But still, stuff like that happens almost on a daily basis whenever trying to fix something...)

              Last edited by r-p; 10-15-2014, 09:32 AM.

              Comment


                Re: Dell 2407WFPb Monitor - Bad Cap

                Hi All

                I've just picked up a Dell 2405fpw and I'm experiencing some flickering issues and distorted colours. Can anyone diagnose what this problem is? I've taken two photos of the issue I'm seeing

                http://s27.postimg.org/xe1khj8jz/IMG_2718.jpg

                http://s27.postimg.org/5ryswup73/IMG_2719.jpg

                Just wondering if its the panel itself or something I can replace (whether it be a bad cap or logic board/port etc)

                Thanks in advance

                Cameron

                Comment


                  Re: Dell 2407WFPb Monitor - Bad Cap

                  Sorry for the crappy photos I didn't realise they were this small. What I'm seeing are blue/green lines more pronounced on darker backgrounds or images (even videos). The lines aren't static, if I'm watching a video the artifacts will move around? Hard to describe.

                  Comment


                    Re: Dell 2407WFPb Monitor - Bad Cap

                    https://www.badcaps.net/forum/showthread.php?t=39740
                    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

                      Sorry. Round two.

                      Attached photos. Have tried factory reset, DVI port/VGA port (same prob). Oddly different backgrounds and colours seem to be fine, in the last photo just by highlighting the icon it seemed to go away

                      Also tried running this tool which seemed to work (I think it was a coincidence) for about 30mins and then it went back to being problematic.
                      http://en.community.dell.com/support...529/t/18688000

                      Just not sure what it is? Does anyone know if its the panel itself? I'm not sure of the symptoms of a bad cap or logic board as its still powering on and functional despite the artefacts.
                      Attached Files

                      Comment


                        Re: Dell 2407WFPb Monitor - Bad Cap

                        Have you actually opened it up and looked inside??

                        Those are the pictures we need.
                        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

                          Hi there a new member here I have owned my dell 2407wfp for just over 8 years and its been fine - up until today

                          I had it connected up to one of those intelligent power extensions, when my PC is turned on, it turns on the monitor, when my PC is shutdown or put to sleep then the monitor turns off.

                          --back-story, please ignore information about PC as it's definitely the monitor with problems--
                          This morning I turned on my PC and was greeted with what sounded by rustling crisp packets followed by a pop. I thought something was wrong with my PC so I turned everything off at the wall and went to inspect the PC. I replaced the PC PSU with a spare and tried again, this time I was close enough to hear another pop/bang from the monitor instead and noticed it was not powering up.

                          I tested the fuse for the plug on the monitor and found it was fine, so I tried powering it up again and it just produced the same pop sound without powering up.

                          So fast forward to now and I have taken the monitor apart to check for damage. I was hoping there would be scorch marks or obvious signs of damage so I could look into replacing parts instead, but the power board doesn't seem to have any obvious (at least to me) signs of damage. I can see cream stuff on a few of the parts but I am assuming this is just glue.

                          Anyway, here are some pictures, hopefully the quality is good enough:





                          (also added as attachments)

                          I don't really have a great understanding of how all this works, I do have some very basic electronics understanding and have a voltmeter if someone could point me to where to poke to test various parts (I understand enough not to plug it in while all the high voltage stuff is exposed)

                          Thanks for any help with this.
                          Attached Files

                          Comment


                            Re: Dell 2407WFPb Monitor - Bad Cap

                            I can see in your 3rd photo that R670 is burnt, and it's just out of view, but it looks like C605 has the usual chemical leakage at it's negative lead. In all, there will be about 8 to 10 components needing replacement to get this board working, some of them involving rather tricky soldering of tiny surface mount components. http://home.comcast.net/~tomdempster...%20Service.htm

                            Comment


                              Re: Dell 2407WFPb Monitor - Bad Cap

                              Hi. I was given one of these dead 2407WFP monitors before Christmas. At the time I worked out that F601, R670, C605 and Q651 had failed. I was able to get the fuse, 0.22ohm 2W fusible resistor and 2SK3502 mosfet from WES but had to wait and get the 120uF/450V capacitor from Element14. Anyway, I didn't get around to it until a few days ago, and after replacing these parts, the monitor still has no power, but no bang also. I am getting voltage on the main C605 capacitor, so that is ok. After reading through most of this thread, I went through again, and found Q654 had short from collector to emitter. The smd ic's appear to be ok, no cracks, but I will order them anyway.

                              Comment


                                Re: Dell 2407WFPb Monitor - Bad Cap

                                Hi all,

                                I've just signed up to this forum as this thread contains so much useful and interesting stuff. ;-)

                                My mate bought himself a new monitor because his (2006) Dell 2407WFPb 'went pop' and I managed to get it off him before he threw it away.

                                Upon inspection it seems the (2006) PSU has suffered the 'std' failure with the 120u 450V cap blowing (leaking from one leg) and taking some other stuff with it. ;-(

                                Now, I've received a 'new' (cheap) PSU (2007) from the far East but (as expected) it has the same age components and specifically same makes of caps in it. So, rather than just installing the new PSU I have been using it to compare component values (following many of the posts in this thread) and I've removed and put the caps from both old and new PSU's on a little ESR meter to see how they compare. In case it shows anything (of use) I'll post my findings here (to the best of my ability):

                                Vloss%, Capacitance(uF), ESR (ohms).

                                C605, 120u, 450V, Elite.
                                New = 0.8, 113.7, 0.4.
                                Old = Unknown

                                C703, 220u, 35V, Chemi-con KY ?
                                New = 1.0, 230, 0.04.
                                Old = 0.9, 213, 0.13.

                                C622, 1u, 100V, Lelon.
                                New = 0.8, 1.3, 2.2.
                                Old = 0.5, 1.1, 3.5.

                                C606 / 611, 47u, 50V, FOAI ?
                                New = 0.8, 44, 0.33.
                                = 0.8, 44, 0.33.
                                Old = 1.5, 42, 1.2.
                                = 1.3, 45, 0.6.

                                C711 - 715, 470u, 35V, Elite.
                                New = 0.9, 468, 0.03.
                                = 0.9, 469, 0.03.
                                = 0.9, 473, 0.04.
                                = 0.9, 468, 0.04.
                                = 0.9, 466, 0.04.
                                Old = 0.9, 462, 0.07.
                                = 0.9, 475, 0.07.
                                = 1.3, 479, 0.07.
                                = 0.9, 465, 0.07.
                                = 0.9, 474, 0.07.

                                Now, not sure how relevant any of that is but it might say something to someone?

                                I seem to also have an open cct 1K SM resistor (R669), Q651 (N Channel Mosfet?) is short all-ways, R670 (R.22) o/c and based on some quick DMM resistance comparisons between new and old boards, the two SM ICs (601 / 651) didn't compare equally so I've taken them off ready to replace.

                                Other components often referenced, the bridge rec and fuses are ok, ZD601(15V zener ?) tests like a straight diode on a DMM diode test and R623 (4R7 SM) tests ok also.

                                So, I think I might replace all the caps on the 'new' board with 'good' makes and then check to see if the screen works again. Then I might replace all the caps on the old board (while I'm ordering one lot) and the other components mentioned and see what happens with that fitted.

                                Any thoughts / advice on that or any of the above welcomed. ;-)

                                Cheers, T i m

                                Comment


                                  Re: Dell 2407WFPb Monitor - Bad Cap

                                  FDAI is actually FOAI,

                                  The weblink is:
                                  http://www.chinafoai.com/eproducts.htm

                                  and the cap details for the CD112A series can found at:
                                  http://www.chinafoai.com/ep12.htm

                                  I found it thru the same link provided by 'toasty'

                                  look in 'F other'

                                  hope it helps, if i'm not too late..


                                  Originally posted by thewzard View Post
                                  Alright so this is what I have come up with for the power board. This is as far as I can go for today. I cannot find the FDAI brand anywhere and I can't pull the specs from ELITE's site from any browser. Hopefully Elite's site will work better tomorrow. Has anyone heard of the FDAI brand?

                                  EDIT: I took toasty's link from earlier () and altered the link to reflect the different series ( and ) and it worked!! All I'm missing to complete the power board is to figure out the FDAI mystery.

                                  FDAI (I think)
                                  50V 47uF
                                  U32 105C
                                  CD112A
                                  Picture available if necessary
                                  Measurements not available*

                                  Jamicon
                                  100V 1uF
                                  TK P105C
                                  624C2(M)
                                  Picture available if necessary
                                  Measurements not available*

                                  Elite
                                  35V 470uF
                                  EJ(M) 105C
                                  (C)0616 FET
                                  Picture available if necessary
                                  Measurements not available*

                                  Elite
                                  25V 220uF
                                  ES(M) 105C
                                  (C)0620 FET
                                  Picture available if necessary
                                  Measurements not available*

                                  Elite
                                  450V 120uF
                                  PW(M) 105C
                                  (C)0623 FET
                                  Picture available if necessary
                                  Measurements not available*


                                  *I felt confident with this process and I didnt measure the caps. I now know that it was a foolish mistake on my part but it was partly because of the trouble im going through to get the measurements. My ruler wasnt made for this, its long and bulky and the measurements don't begin at the tip of the ruler. What are you guys using to measure?

                                  Comment


                                    Re: Dell 2407WFPb Monitor - Bad Cap

                                    After about 8 years my 2407 wouldn't turn on. Found this post and identified the following damaged components:
                                    • C605 (corroded pin)
                                    • F601 (high resistance)
                                    • Q651 (low resistance between all pins)
                                    • BD601 (low resistance between pins)

                                    Replaced with the following parts:
                                    Plugged it in and it worked! Thanks to everyone in this thread.

                                    Comment


                                      Re: Dell 2407WFPb Monitor - Bad Cap

                                      I have quite a funny story to tell.

                                      I've replaced C605 and other caps on PSU board after 6 years of use in advance to avoid any damage, used nippon cap for a big one and thought I was safe.

                                      Imagine my surprice when like a month after that I heard POP sound and monitor went dead. I disassembled it and saw that 1 leg of C605 was dis-soldered for w/e reason (probably that's on me, bad soldering?). Cap itself looks totally okay. Examining the board showed clear signs of Q651 burnt, also main fuse's dead as well. Diodes that are close to Q651 seem alright, although I'm not quite sure about IC651, there is like 42 Oms resistance between some of its legs. I then got monitor working using trick described in post #155 with an old brick PSU from something (printer?) of HP origin, but it's a bit weak I guess, it's 18.5V, 3.5A, 65W. I run brightness on 15% for now, but I hope to get internal psu repaired.

                                      Can some1 tell me if IC651 having 42 Oms resistance is actually okay?
                                      Can a resistor be burnt with no visual signs of that? What resistance R670 is supposed to have?

                                      I actually don't know much about electronics, so I'm like lost in a forest and need a guide =P

                                      Comment


                                        Re: Dell 2407WFPb Monitor - Bad Cap

                                        Hey guys,

                                        I have need your help. My 2407 has gone. So I turned the problem down to the power supply. I measured a bit and found out that I have not the common problem with the C605 and the other components.

                                        Only R603 was obviously burnt and I changed it with a working on. But the power supply doesn't give me the 19V.
                                        But I have the 310V over C605 (I'm from Germany).

                                        So now it's your turn, because I do not have any idea what to do next.

                                        Regards

                                        Comment


                                          Re: Dell 2407WFPb Monitor - Bad Cap

                                          Hey Guys,

                                          nobody wants to help me?

                                          So I did the audiojack mod to verify the display and the other boards are working. And they do!

                                          So the problem is really the power board. Does anybody have an idea what to check next. 19V are not present!

                                          Regards

                                          Comment

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