new P2715Q cursor/window elements duplication

Just received and connected a new Dell P2715Q monitor to my 2013 MP as a second display. It sits to the left of the original Apple 27" Thunderbolt display. The only set up slip-up was connecting the cable to the DP out port at first rather than the DP in port of the display but this was quickly corrected. The display image color and sharpness are great except for one problem. The right hand 1 inch of the display image is distorted. This distortion produces duplication/triplication/quadruplication of some of the interface elements like the cursor, right edge of a Safari browser window, and the notifications symbol in the menu. The background image is out of focus in the same strip of the monitor screen.

I separated the two displays to check for some electromagnetic interference between the two displays but this had no effect. There were no other sources of electromagnetic interference in the immediate area. I reset the display to factory defaults although I hadn't changed any. My Google search on the issue didn't find any help.

Has anyone else had this distortion/duplication problem? Does anyone have any suggestions for resolving the issue? Do you need anything else explained to understand the problem better?

Thanks for the help.
Brian

DeltaMac said:

Does your Dell display show any distortion in that part of the screen when you run the built-in diagnostics? You have to disconnect the video cable from the display to run the diagnostics.

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DeltaMac, I just ran the built-in diagnostics. The various color screens show no non-uniformity in the colors or missing pixels. The text diagnostic does not cover the right edge of the screen - being located in the central viewing area. So there is no distortion in the text diagnostic.

very interesting

I tried using Grab to get a screen capture of various windows that show this distortion at the right edge including a Word document with random letters. This Word document when moved to the right edge of the screen exhibited this distortion of the letters but the screen capture of the same document which was exhibiting this distortion did not capture the distortion. Instead, the letters in the captured image looked normally formed and non-ghosting/duplicated even though they were distorted in real time viewing (unless the screen capture was moved into the distortion zone). I was unable to capture distortion of anything else.

mavericks problem

I usually run in the latest Mavericks rather than Yosemite because of the decreased contrast of the typeface which is difficult for me to read. I had a partition on an external disk with Yosemite and switched to that to see what effect it would have on the duplication/ghosting on the right edge of the P2715Q. Low and behold, the distortion was not present. It must be a problem with the drivers in Mavericks.

Are there any updated drivers I could download that would eliminate the distortion in Mavericks?

Thanks,
Brian

resolved!

edanuff said:

This is a problem that was fixed in Yosemite. Some people have claimed they have fixed the problem in Mavericks with higher quality Accell video cables, but the only official fix is to run Yosemite.

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Continued to work on this issue. In Mavericks, opened the built-in screen menu and went to Menu/Display/MST. I found that it was in the Off position. I toggled it to Primary. The distortion was no longer present! I then toggled the menu item to Off and the distortion was back again. Finally, I toggled the menu item to Secondary and the distortion was gone again. The screen looked great.

That proves that the problem was resolved by adjusting a built-in monitor setting - MST. Neither Yosemite nor a new cable is necessary.

On restarting the computer and monitor 7 hours later, everything is still fine.

Brian

refresh rate

edanuff said:

When you switched the monitor to MST, you caused it to go into 30Hz mode (see page 34 of your user manual). That's why you're not seeing the problem. If that's acceptable to you, then that's fine, but most of us with these monitors want them running at 60Hz.

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Thanks for the input. I checked the System Info (see image) and you are partially right. It is not running at 60HZ, it is running at 59Hz . Note that I am using the Largest Text scaled setting because I have reduced visual acuity. Also note that my primary Apple 27" TBD is set at 1600x900. At these settings, I find that the text size on the two monitors is roughly equivalent and easy to scan back and forth between the monitors.

I find the extra sharpness of this monitor to be useful. I will be using it primarily for photo editing and coding rather than gaming or video. You are right that if I used a smaller text size setting, it runs at 30Hz. I don't think that will be an issue for me.

Brian