External Monitor Screen Wobble

[ken davies]

Hi.



I have a recurring issue on the external monitor connected to a MacBook Air. The screen is connected via Thunderbolt to VGA connector. The screen is a Dell 26" and when connected to my old MacBook there was no issue. The Mac connected now is a 11" Macbook Air 2014.

The issue can only be described as a screen wobble. issue can be seen here.

 

[ken davies]

Sorry forgot to upload video. The speckles are just dust on the screen

If anyone has any ideas how to fix this or what has caused it, I need help. It doesn't do this all the time, just every so often and it will do it for a couple of minutes then stop

 

[Cory Cooper]

Hello and welcome.

-Which versions of OS X on the MacBook Airs?
-Do you have any fluorescent lights, dimmer switches, or anything else that could cause interference near the Mac/Dell display?
-If you connect it to the old MBA, is the issue still not present?
-Are you using the same adapter on both Macs?
-Have you tried both extended desktop and mirror display settings?
-Is your Thunderbolt to VGA adapter an Apple unit or third-party?

First things to try would be:
-Check the connections
-Change the resolution in System Preferences... > Displays

C

 

[ken davies]

Hi. The connector is Apple
Using OS 10.10.5
With the problem being intermittent you don't know if making a change to such things as resolution etc will effect it
The Mac is normally set to extended desktop

 

[Cory Cooper]

Thanks for the additional information.

I took a look at the video again. If it is intermittent, then it sounds like something is causing the interference.

Do you happen to have another external display (either yourself or at another location) you could test the Mac and adapter with?

C

 

[ken davies]

I will do that, I think interference too, but never seen this before. What can cause such interference?

 

[Cory Cooper]

Devices such as fluorescent lights, dimmer switches, microwave ovens, improper mains ground, bad cables, ham radio transmitters, etc. Strange that it is intermittent.

C

 

[honestone]

Just out o curiosity, does it happen in a another, more "isolated" room?