Vertical black bar at the left side of an external display

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Level 1

1 points

Vertical black bar at the left side of an external display

On Yosemite when I set the resolution to 1920 x 1080 there appears a vertical black bar at the left hand side of the external display and you can't see the whole screen on the right side of the screen. This happened with Mavericks too. Other resolutions don't have the same problem and with Snow Leopard this problem doesn't exist. When I take a screenshot the screenshot is perfectly fine and doesn't have the black bar.

What to do?

The display on my iMac is broken so I don't know if it would have the same problem as with the external display.

Here's a pic to explain it better than I can:

iMac, OS X Yosemite (10.10.2)

Posted on Mar 16, 2015 1:42 PM

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Answer 1

pmiles

Level 6

16,014 points

Mar 17, 2015 7:47 AM in response to PankreasKivi

What computer (i.e. 2011 Mac Book or ? you said it wasn't the iMac) is this display attached to?

Can you directly connect the display to the computer without the use of the adapter?

Does System Profiler correctly identify the display and resolution?

Does it correctly identify your display in System Preferences > Displays? It should list the name of your display on the top bar. If it's wrong or not listed, try holding the option key while this window is open and click on the Detect Displays button.

Have you tried using a different scale for the display? Smaller or larger to see if it fills the screen or always offsets the image.

Have you tried resetting the PRAM and SMC?

How to Reset NVRAM on your Mac - Apple Support

Try booting up in Safe Mode to see if it resolves the issue?

OS X: What is Safe Boot, Safe Mode? - Apple Support

You said it doesn't work under Mavericks or Yosemite... so it's only ever worked under Snow Leopard? When was that? Meaning that you haven't had this display connected to a computer for quite some time. It's possible it could be the adapter but you would have to test it with another computer to be sure.

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Answer 2

Mar 21, 2015 11:11 AM in response to PankreasKivi

similar (but not exactly the same) problem here after the upgrade to 10.10.2 on a MBpro and external 3840x2160 tv (seiki).

I just posted details below. In my case the black borders are on all four sides:

black border with MBPro and 10.10.2 on external 3840x2160 TV (worked with 10.10.1)

i think that in my case the os is generating a wrong video timing, perhaps in an attempt to compensate a presumed overscan (which some TVs do, but not mine, and in 4k mode i don't even have a way to enable overscan).

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Answer 3

PankreasKivi Author

Level 1

1 points

Mar 17, 2015 3:02 AM in response to pmiles

"If you connected your Mac to a TV and the images don’t fill the TV screen, try turning on Overscan.

Choose Apple menu > System Preferences, click Displays, then click Display.
Click Options, then select Overscan."

When I click Display there is no Options to click.

Also it's not a case of overscan since the picture is of right size, it just isn't centered on the display. The picture of desktop is moved to to the right so that there's a black bar on the left side of the display and on the right side the picture is cut so you can't see the whole desktop. I don't know if I'm explaining this clearly enough.

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Answer 4

PankreasKivi Author

Level 1

1 points

Mar 16, 2015 2:46 PM in response to pmiles

Samsung T24C300EW

I guess I'm not using any driver. I just connected the display using VGA cable and minidisplay port to VGA adapter. With Snow Leopard it's been working fine. Maybe I need to try with a driver?

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Answer 5

PankreasKivi Author

Level 1

1 points

Mar 17, 2015 10:03 AM in response to pmiles

I have a 2009 iMac. The display on it is broken so I use an external display. Only way to do it is using the minidisplay port and an adapter. I have had this set up for a year now (ever since I broke the screen on the iMac) with Snow Leopard as the operating system. Haven't had any problems with it.

Last year I partitioned my hard drive to test Mavericks on the other half of the hard drive. It detected the external display but when I set the resolution to 1920 x 1080 it offset the image. With other resolutions the image was fine. Didn't feel like fighting with it and gave it a rest and continued using Snow Leopard. Now that I tried Yosemite yesterday the same problem exists: detects display, works fine as long as I don't set the resolution to 1920 x1080. Right now at this very moment I'm using Snow Leopard and the problem doesn't exist.

I would like to try Yosemite but I'd also like to use 1920 x 1080 resolution and still see the whole image.

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