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Dual Dell U2412M Monitor DisplayPort 640×480 Resolution Woes

May 12, 2013

I purchased a pair of Dell UltraSharp U2412M 24-in Widescreen Flat Panel monitors and a Ergotron DS100 Dual-monitor stand for my desk recently.  I connected both monitors to my Lenovo ThinkCentre m92p Tiny desktop computer which has two DisplayPort interfaces and Microsoft Windows 7 Professional SP1 installed.  The Windows 7 Balanced power plan (default) is configured to Turn off the display after 10 minutes and Put the computer to sleep after 30 minutes.  Although the resolution of the monitors is configured to 1920×1200, each time my computer returns from sleep mode the resolution of both monitors reverts to 640×480. One could argue that since power consumption is so low, (39 watts peak and 19 watts at idle according to my Kill-a-Watt) on the m92p Tiny desktop that I could change the option to Put the computer to sleep to Never and leave Turn off the display at 10 minutes (each monitor consumes 24.5 watts when on and 0.6 watts in Standby mode).

Since I always forget to turn off the computer when I am finished using it, I wanted to leave the default power plan to Put the computer to sleep after 30 minutes.  I discovered that if I unplugged the DisplayPort cable from the back of each monitor and then plugged it back it when the computer was out of sleep mode the resolution would be restored.  However, this was a tedious task and after two days I was beginning to become frustrated with the issue.

Anytime I have a problem with a peripheral it is typically a driver issue.  The m92p Tiny uses Intel’s integrated HD Graphics 2500, so I visited the Intel Driver Update Utility webpage to ensure that I was using the latest graphics driver.  I found that the driver I was using (Driver Version 9.18.10.3071) was up-to-date.

Next I decided to search the Dell Community Support Forum to seek a solution.  I soon realized that this problem was not isolated to the U2412M, in fact there were several other posts that mentioned the problem occurring with the u2711 as well.  Some simply decided to switch to the DVI interface instead, which worked flawlessly.  A few unsuccessfully replaced the DisplayPort cable with a “more expensive” cable only to find that the problem resurfaced once the computer went back into Sleep mode.  Others returned their monitors for a replacement, unfortunately in each of those cases the replacement also exhibited the same problem.

RESOLUTION: Finally, as a last resort I started to manipulate settings on the monitor itself.  This was a time consuming process because I had to wait for the computer to enter sleep mode after each change to determine if the change resolved the issue.  In the On Screen Display (OSD) menu, under Other Settings I found an option DDC/CI and set it to Disabled.  This resolved the problem for me.  Apparently ,DDC/CI allows a computer with a supported graphics adapter to adjust monitor parameters such as brightness and color balance, or to initiate degaussing.  Oddly enough, according to Intel DDC/CI is supported on the HD 2500 graphics adapter.

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One Comment leave one →
  1. Scotty permalink
    November 9, 2015 11:08 pm

    You ROCK! Works for Windows 10.

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