Alienware 17 R3 lid switch repair (how to)?

Hi,

Do you mean that the screen stays on, laptop doesn’t go into sleep mode, when the lid is closed, is this correct?

Does “all tests” include the following? Apologies if you have them tried already.

Just verifying that you checked the advanced power settings Power Buttons and Lid -> Lid Close Action is set to sleep

If it is, I don't know your laptop but try running a magnet along the area between the keyboard and the lid especially around the power button and check if that turns the screen off and on when you move the magnet.

If it does turn the screen on and off then perhaps the magnet has slipped in the lid. It will be located behind the bezel below the screen above where you placed the magnet on the case. The service manual (linked below) details how to access the display which should help in gaining access.

If the magnet makes no difference then the problem is most likely in the power button board as that is where the switch may be

If it is the power button board, here's a link to the service manual taken from this webpage. Scroll to p.37 to view the necessary pre-requisite steps and then the procedure to remove the power button board