Display issues

[magiccarpet]

I have a mid 2015 iMac Retina 5K, 27-inch. I've had to replace the screen from a donor iMac (same model) and am now getting an odd issue. The screen will suddenly have a blue cast and then drift back to a normal color temperature over a few seconds. It'll stay like that for a good while then have a blue cast again before drifting back. Have I damaged a sensor or maybe cable during the screen replacement or could the donor screen be faulty? Not sure how to proceed and any advice gratefully received!

Thanks.

 

[IngoX]

The iSight Camera-module has an ambient light sensor that affects screen brightness and color temperature with True Tone. It should not be affected by the screen replacement if you were careful.

But maybee its possible that bluish light from the screen itself is bleeding into the sensor if something was not correct during reassembly, and fooling True Tone to give too much blue-tint?

You should be able to trobleshoot if it is a sensor problem by turning off True Tone and auto adjustment of brightness.

 

[magiccarpet]

Hi IngoX, it doesn't have True Tone as it's too old. Is it still likely to do with an ambient sensor though? I have the old screen which I can lift the other camera from if that looks likely to be the issue. If it's a light bleed issue though then maybe a strip down and rebuild will help.

Edit - thinking about it could I shine a blue light in to check it makes the screen color change?