MacBook Screen Does Not Work, External Monitor Does

displayhardwaremacbook provideovideo-adapter

Update 2012-03-19: I never figured out what the problem was because the screen started to work again after reinstalling OS X 10.6 for a second time. I sold the Mac on eBay a few months afterward (I explained the full history ;).

Original Post: My Late-2008 Aluminum MacBook Unibody screen doesn't usually turn on. External displays work via the Mini-DisplayPort.

Sometimes when power is not connected, the lid is open, and I have the external display connected, the internal monitor will work! When it works, it stays on until reboot.

I've tried:

I've been told by an independent, authorized Mac repair company that the logic board needs to be replaced. That seems a bit excessive to me, although I've read many similar diagnoses online.

Any other ideas?

Best Answer

I would put a lot of weight in a technician that sees many macs as they really don't have any reason to mislead you. You can also get a second opinion if you don't feel the one you got the first quote listened to your concerns or explained how he arrived at that guess.

Do make sure you look carefully - when the backlight goes out on a LCD - there is so little light coming through it is hard to tell if the panel is drawing fine and the light is missing or the panel isn't being driven.

Without opening the mac and trying to replace things (and especially when it's intermittent) it's hard to know for sure what one piece is failing. If you ask a tech to put percentage chance you will find most situations have multiple causes, but one is much more likely given experience and symptoms.

The next time it goes out - you can use a flashlight to narrow down if the panel itself is not getting signal or it's just the backlight by looking for the menu and other graphics on the screen getting drawn.

Related Question