External Display Issue

[eddjedi]

I'm not sure if this is a hardware or software issue, but hopefully somebody can help.

I recently got a new Macbook Air, it's the 2014 1.4GHz i5 11" model running Yosemote 10.10.1. When hooked up to my external monitor (which is a Dell U2414H) via MiniDisplayPort, sometimes after sleep or the screensaver being active the colours on the external display go strange. If you look at my attachments the first photo is how it looks, the second shows my MBA display side by side for comparison, the third photo is how it looks normally, and interestingly the final one is actually a screen grab taken within OS X rather than a photo, which is why I think it may be a software issue. Disconnecting and re-connecting the MDP cable solves it, but I am concerned that my MBA is only a few weeks old and may have a fault.

Has anybody else seen this issue before? Any thoughts on what could be the cause? I don't think it is the monitor or cable as I also have a Dell work laptop that works with the same setup just fine. Not sure if it's worth mentioning but I usually run the MBA in 'clamshell mode' while connected to the external display, not sure if that could be having an effect?

 

[motrek]

I think this is what you need:

http://www.ireckon.net/2013/03/forc...ix-the-picture-quality-of-an-external-monitor

 

[jdphoto]

I think this is what you need:

http://www.ireckon.net/2013/03/forc...ix-the-picture-quality-of-an-external-monitor

Either this or maybe a bad cable/adapter? Does it get better if you wiggle the cable at either end?

 

[eddjedi]

I don't think this is the exact issue but could be related - as you can hopefully see in the screenshots, Preferences recognise my monitor by its name when working properly, but when the colours go strange it it is listed just as 'Display'. So perhaps it is an issue with OS X recognising the monitor after sleeping?

No I'm fairly sure it's not the cable, adjusting it doesn't affect it, only physically unplugging it.

 

[eddjedi]

I just noticed on the 'Color' preference panel it gives several 'Display' presets. All of these apart from one shows the weird colors!

 

[motrek]

I don't think this is the exact issue but could be related - as you can hopefully see in the screenshots, Preferences recognise my monitor by its name when working properly, but when the colours go strange it it is listed just as 'Display'. So perhaps it is an issue with OS X recognising the monitor after sleeping?

No I'm fairly sure it's not the cable, adjusting it doesn't affect it, only physically unplugging it.

Did you try the link I posted? I'm 75% sure it will solve your problem. It was necessary for me to get correct colors on my quad-HD display at all.