Maarten, start off by trying what Apple suggest:"LCD Display is tinted another color.
Reset the parameter RAM.
- While the computer is off, with your left hand, hold down the Apple key, the option key next to it, and the letter R. When you have them all pressed push the power button with your right hand and then quickly move that hand to hold down the letter P. Keep the four keys pressed while the computer starts up.
- Make sure you hold down the four keys (P-R-Command-Option) while the computer starts up. When you keep all the keys held down, you will hear the startup chime over and over again (about every ten seconds) until you let go. After you hear the second chime, you can let go of the keys.
- If you didn’t hear at least two startup chimes, repeat the procedure above and try again. It’s important that you hear two startup chimes when performing this procedure. This indicates that you have successfully reset the computer’s PRAM (Parameter RAM).
Does the computer display video after successfully resetting the computer’s PRAM?
Yes: Problem resolved. Restart the computer from the Apple menu and make sure the computer display is no longer tinted another color.
No: Continue to the next step.
Connect an external monitor to the mini-VGA port. Does the external display exhibit the same color tinting?
Yes: Replace the logic board.
No: Check the TMDS cable connection. If connected and same color tinting persists, replace the TMDS cable. Does color tinting persist after changing the TMDS cable?
Yes: Replace the LCD display panel.
No: Problem solved. Restart the computer from the Apple menu and make sure the computer display is no longer tinted another color. ."If that doesnot work, then it is possible that you have some serious issue with the video processor. A reflow may help you with that, but again check out the above first, then let us know what you find. Hope this helps, good luck.