My MBP will no longer detect external displays. It was working fine a few hours ago at work, I got home and plugged in the external display as usual and turned on the machine and nothing. Using the "Detect Displays" does nothing. I have tried re-plugging the mini DVI display port adapter and have tried using a different monitor with a different monitor cable. I have tried shutting down and booting without the adapter plugged in and then plugging in the adapter. Nothing works. Is there some trick to force my MBP to see and use the external monitor?
More Information: When I plug in the display port the LCD screen goes blue for a moment. Checking the Graphics and Displays display connecter shows
Status: No Display Connected
Best Answer
I have had a similar problem (albeit with a Powerbook) and I had to change my DVI-VGA (back then we didn't have Mini-DP). It was working until one day it simply stopped working. Since I had a lot of displays at home, I tried -like you- different cables and displays to no avail until I found another adapter and boom, it worked.
Another way to test this is go to an App Store or similar with your machine and your cable. Try to make it work there. If it doesn't, they will have extra adapters to rule out that possibility. If a new cable, display, adapter also fails, then your Mini-DP port could be failing and that requires an App Store anyway…