Help with MBP and Dell monitor?

Discussion in 'Mac Accessories' started by absurdio, Dec 31, 2007.

  1. absurdio macrumors 6502

    Aug 25, 2003
    RI, Chi, and/or NY.
    Arright. Here's the scoop.
    I've got a 2nd gen 15" Macbook Pro, and I just today received the Dell E248WFP monitor I'd ordered.

    The problem: I can't make it display ANYTHING for longer than a fraction of a second.

    I've got the monitor hooked up to my MBP by dvi cable (yes, securely). When I turn the monitor on, there'll be an image for literally half a second or so. Then everything returns to black. Similarly, when I change the Dell's resolution in Display Preferences on the MBP, the image appears for the same fraction of a second, then disappears.

    What in hell is going on?

    Edit for the sake of some additional details: "Detect displays" gets no reaction out of the monitor. Strangely, if I turn off mirroring, some of my windows do go over to the Dell monitor (i think), but the monitor stays black, and you can't see them (I only know they're there because of the brief half-second just after turning the monitor on). Further, "Dell E248WFP" appears in the Displays icon in the menu bar. So by all accounts, it SEEMS like my MBP is recognizing the monitor, and it SEEMS like the monitor is getting some signal, at least some of the time. But why the screen goes dark instantly, I cannot figure out.
  2. Consultant macrumors G5


    Jun 27, 2007
    Normally Mac laptops auto-detects the display. Perhaps the refresh rate of the external is wrong?

    Go to System Preferences/ Displays / Arrangement

    What do you see there?

    Have you tried rebooting?
  3. absurdio thread starter macrumors 6502

    Aug 25, 2003
    RI, Chi, and/or NY.
    The Arrangement tab does indeed show me two displays. At the moment they're mirrored (because having open windows on a display I can't see doesn't do much good). Sometimes switching from mirrored to not-mirrored (or vice versa) is enough to make the monitor light up for one of those precious half-seconds, but still no more than that.

    I have tried rebooting (in various states of connected, too), but I'll give that another go.

    Edit: Having tried that, I'm afraid it's the same story. When the MBP got past the gray screen to the blue log-in screen, the Dell turned blue for an instant, and then returned to black. *Sigh*

    Another edit: If mirroring is on, I get a Displays window labelled DELL E248WFP at the top. Under the Display tab there, the Refresh Rate is shown as 60 Hertz, and though it's a dropdown menu, the only other option (75 Hertz) is grayed out. That might be more relevant information.
  4. absurdio thread starter macrumors 6502

    Aug 25, 2003
    RI, Chi, and/or NY.
    Just to put the thread to rest: it was a defective monitor. Got Dell to replace it, hooked it up, and the replacement works fine. What an aggravation.
  5. atwaterkent macrumors newbie

    Dec 24, 2008
    Monitor Shuts off after Power Up

    This is for a Dell Monitor - other monitors may be similar.

    Cause of power going off:

    There is a bad 1000uF, 16V cap on the power supply board.


    Replace cap. Radio Shack sells a 1000uF, 35V cap for $2. This will work.

    Why did the cap go bad?

    The cap is too close to a heat sink and over heated.

    What does this cap do? This cap sends a signal to an IC which keeps the monitor 'on' after the power switch is pushed. When the cap is weak, AC ripple voltage is applied to the IC and it sends a signal to shut the monitor off.

    Opening the Monitor:

    These monitors are difficult to open.

    The two plastic pieces snap together and must be pried apart with a flat screw driver.

    After removing the stand, you need to insert a flat screw driver at the bottom of the screen where two slots are located. Then work the screw driver around until the two plastic pieces are separated.

    Remove the cover plate and unscrew the push button circuit board.

    Unplug the monitor cords from the driver board and remove the screen.

    Unscrew the mounting screws from the power supply board and remove.

    You will need to pinch the plastic support in the middle of the board to remove.

    Cap Replacement:

    Cap is located near a copper heat sink and the value will be on the side of the cap. It will be bulged up on the top. You will see burn marks on the board surrounding the cap. Unsolder the cap.

    Install the new cap and solder. Make sure you connect + of the cap to + marked on the board.

    Be careful not to solder across joints.

    Keep leads long so you can bend the cap as far away from the heat sink as possible.

    Reassemble monitor and turn on.

    This should solve the problem.

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