Dell 2407WFPb LCD monitor dead

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • sean5302
    Member
    • Jun 2006
    • 10

    #1

    Dell 2407WFPb LCD monitor dead

    My beloved Dell 2407WFPb RevA00 has died.

    I've stripped out the 4 boards and am missing any obvious fault. I can't see bulging caps, burnt wires or components.

    I've checked many fuses but may be missing something. I cannot light the mains power on led on the switch panel, although there are many voltages around the power supply board. I don't know much about switch mode power supplies.

    The fuses I've checked as Ok are these. I seek help, please. Are there more fuses lurking or am I on the wrong track?

    All help greatly welcomed. I've searched the forum and can't see what I need.

    Fuses checked:
    Inverter board F1, F2, F101.
    PSU F601, F701
    Logic board F9
    USB board F801, F802, F803, F804.

    My problem started with the power button falling off the monitor ( well known fault) and I had to use a pen nib to switch it on. Now, all is dead.
    This monitor cost me £430 in 2009 and I like its style, its fine pitch and its size. I'd love to fix it, if you can help.
  • sean5302
    Member
    • Jun 2006
    • 10

    #2
    Re: Dell 2407WFPb LCD monitor dead

    Just thinking about what I've written:

    1. I need to research switch mode power supplies.
    2. I'm wondering whether I've broken something on the front power switch. This is just a button switch on a ribbon cable. It has an LED which should light when the power is on. Anyone know what voltage this would use? I'm guessing 5V DC
    3. How would I get a circuit diagram for my monitor? The Dell site doesn't show anything.

    Comment

    • selldoor
      Slow Learner
      • Dec 2010
      • 7870

      #3
      Re: Dell 2407WFPb LCD monitor dead

      Hi - if you have been a member since 2006 you should know the drill. We need pictures. Fronts and backs of the boards clear enough to read the numbers. and not obscured by flash, posted using the manage attachments and sized accordingly. I see you are in the uk so another light day should be along sometime in the next month .
      Dell schematics are difficult to find so that makes the pics a necessity.

      A close up of the switch ribbon where it connects to the board may be useful. If it is only a switch perhaps you can try a jumper across where it connects?

      Did it come with a 3 year warranty? still valid?

      Just watched this http://www.youtube.com/watch?v=WsFQj...der&playnext=1
      some guy fixing his on off button and see its more than just a button on a ribbon.
      So perhaps close up pics of the button board will help rather than the ribbon connector.
      Last edited by selldoor; 01-28-2012, 12:22 PM. Reason: just seen utube
      Please upload pictures using attachment function when ask for help on the repair
      http://www.badcaps.net/forum/showthread.php?t=39740

      Comment

      • sean5302
        Member
        • Jun 2006
        • 10

        #4
        Re: Dell 2407WFPb LCD monitor dead

        Thank you.
        Yes, the Youtube video is of the same monitor. I'll post some pics today.
        The ribbon cable has 18 wires which push into a clamp connector. A poor arrangement as I cannot readily check that each wire has a good connection. It has a clasp which turns through 90 degrees to lock the ribbon into the female connection on the logic board.
        There are 6 LEDs and 6 button switches on the bit of circuit board containing the ribbon cable.
        I've been doing some continuity checks with my test meter to try and see which wires connect to which switch and which LED on the ribbon cable. I'm trying to see whether it's this ribbon cable board that is not switching and, now you've prompted me, whether the connection to the logic board is OK.
        I'll post pics later.

        Comment

        • sean5302
          Member
          • Jun 2006
          • 10

          #5
          Re: Dell 2407WFPb LCD monitor dead

          Pics
          Attached Files

          Comment

          • sean5302
            Member
            • Jun 2006
            • 10

            #6
            Re: Dell 2407WFPb LCD monitor dead

            A few more.

            These are of the logic board connector for the ribbon cable.
            Attached Files

            Comment

            • jetadm123
              Badcaps Legend
              • Feb 2010
              • 2169

              #7
              Re: Dell 2407WFPb LCD monitor dead

              There have been quite a few problems with this model and very few solutions. The link below is fairly long, but may help you. If you have the same board then post #77 may help. Somewhere in that thread is a link to the schematic. And some enterprising member bypassed a portion of the power supply to get it working. The thread is well worth reading.

              https://www.badcaps.net/forum/showth...light=2407WFPb

              Comment

              • sean5302
                Member
                • Jun 2006
                • 10

                #8
                Re: Dell 2407WFPb LCD monitor dead

                Thank you.

                I have read through that thread, which mostly concerns the power supply.

                I'm hopeful that my problem may just be on this ribbon cable and switch pcb.

                A real shame that circuit diagrams and general info isn't available.

                I really don't like the construction of the lead, in the way that it attaches to the pcb holding the switches. It's glorified Sellotape, containing 18 "wires" of printed aluminium, just wrapped over the pcb. Who knows whether there is good conductivity?

                Comment

                • selldoor
                  Slow Learner
                  • Dec 2010
                  • 7870

                  #9
                  Re: Dell 2407WFPb LCD monitor dead

                  Id start at the switch. Multimeter set to ohms on both switch terminals then press the switch (Yes you need three hands) anything? next Multimeter on ohms one lead on a switch terminal then gently drag the other lead across the terminals on the switchboard end of the ribbon and note which 'wire' it is. Repeat with the other switch terminal. Check the continuity over the ribbon connector you can count across the other end to locate the switch wires. If the cable is good and the switch works then we can concentrate on the PS board end.
                  You can of course do the whole thing in one go from the switch terminal to the PSBoard end of the ribbon.

                  At least your connector has the locking strip I have a monitor where there is ribbon from the PSU to the logic board and the lock strip broke. The number of these that break you'd think someone would sell them? Im working on different means of jamming the ribbon into the socket.
                  Please upload pictures using attachment function when ask for help on the repair
                  http://www.badcaps.net/forum/showthread.php?t=39740

                  Comment

                  Related Topics

                  Collapse

                  • Bowline
                    Dell E6400 PT434 type Battery Charging Stuck at 1%. Battery Pinouts?
                    by Bowline
                    My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?

                    Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?

                    My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
                    The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
                    I have tried multiple different Dell power adapters. My Dell...
                    06-11-2025, 10:13 AM
                  • DanPoka
                    Guide me through repairing a Dell p2210f LCD ccfl backlight monitor
                    by DanPoka
                    I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
                    Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
                    This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered...
                    02-15-2025, 05:05 AM
                  • Powderfanupnorf
                    Dell AL440LX power on switch circuit help required
                    by Powderfanupnorf
                    Hi Everyone. First official post so fingers crossed I conform and also manage to get photos to work.

                    So I am requesting some help from anyone who happens to have one of these motherboards to hand and perhaps a multimeter.

                    My board has a single row of header pins for all the front panel stuff (have seen others where they are grouped together differently so thats no help) and the two pins for the power on switch had been previously repaired and I am trying to make a better repair. There looks to be pad and trace damage and im happy to relocate the header pin/pins to...
                    06-24-2024, 01:24 PM
                  • momaka
                    HannStar Hanns-G HC194d LCD monitor repair
                    by momaka
                    Normally, I never post repairs this quick after I do them, because… I am usually very slow. But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
                    03-15-2023, 10:17 PM
                  • Jesus Coder
                    Issues Reviving Old Dell 2408WFPb Monitor
                    by Jesus Coder
                    Hello everyone,

                    I have been having some difficulties reviving an old Dell 2408WFPb PC monitor that I received for free. When I first acquired it, the backlights of the display were on but alas no image was showing. After extensive research on the topic, I went ahead and purchased a new t-con board for the monitor. After installing the board, I was then presented with a new screen that was half black and half green (more so black). I have been unable to figure out what to do next as I have limited knowledge of display electronics. Might anyone on this forum have an idea of what may...
                    06-25-2023, 02:33 PM
                  • Loading...
                  • No more items.
                  Working...