4 Replies Latest reply: Aug 12, 2013 5:48 PM by Neil D
Neil D Level 1 (30 points)

So I recently got an external display, the 24" Dell S2440L. I have it hooked up to my laptop via an HDMI cable. (So there is a MIni Displayport to HDMI) adapter. I run my MBP in clamshell mode (I have a bluetooth keyboard and mouse) and it all works perfectly. Except the occasional flash on the monitor.


It doesn't happen too frequently, but enough that I notice it. The reviews online for the display are excellent, and I absolutely love it. The flashing is just a brief "blink" I suppose in the display. No other issue besides this. I was curious to know if anyone else has this issue with their display. I assume it's got something to do with the cable or computer port, not the actual display. Any thoughts?


Thanks in advance, and I apologize if this is in the wrong subforum.

MacBook Pro, OS X Mountain Lion (10.8.2)
  • MHN Level 1 (85 points)

    No answer here on the blinking, but a suggestion:  If you have a DVI-D port on the monitor, try the Apple Mini DisplayPort-to-DVI-D adapter.  My MBP on an HDMI cable with the HMDI-to-Mini DisplayPort adapter produced a coarser (lower res) image on the monitor; on DVI-D the view on the monitor was every bit as good as on the 15" MBP (non-retina).  I'm wondering whether the blinking is due to some form of loss of sync resulting from forcing the image through the HDMI route; a DVI-D adapter (assuming your monitor has a DVI-D input!) could be used to test the theory.

  • Neil D Level 1 (30 points)

    Nope, it only has HDMI and VGA inputs.Thanks for the reply though! Do you think there's another way to fix this?

  • Neil D Level 1 (30 points)

    Also, another question. Would the adapter have any effect on this? Say if I bought just a cable (mini displayport to HDMI) would that work better do you think? I'm sure it has to do with the cable and not an issue with the actual display.


    Thanks in advance!

  • Neil D Level 1 (30 points)

    Well, for posterity's sake, I got an HDMI to VGA cable (no adapter) and it seems to be working fine!