Macbook no longer detects external Monitor

[CookieCarol]

Hello!

I'm using a MacBook Pro (13-inch, Mid 2012) and running Yosemite on it.

I had my MacBook unplugged and connected to an external monitor. The battery died and so the computer went off. When I turned it back on later, it wouldn't detect my external monitor anymore.

I tried restarting with the cables unplugged and plugging them back in.
I tried opening Color Sync utility and system preferences and neither see the monitor.
I tried rolling my mouse over to the monitor, but it's not there. Just the main one on the laptop.
I tried plugging the monitor into another macbook and that works fine. So it's something on the laptop which is wrong.

If anyone has any possible solutions to this problem, I would greatly appreciate it. Thesis checkpoint deadlines are fast approaching. *sweats*

Thank you!!

 

[barbu]

Sounds like you tried some very good troubleshooting techniques. You could try the good old NVRAM zap and see if that helps:

Resetting NVRAM

1. Shut down your Mac.
2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R.
3. Turn on your Mac.
4. Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.
5. Hold these keys until the computer restarts and you hear the startup sound for a second time.
6. Release the keys.

 

[CookieCarol]

This solved the problem!

THANK YOU!!! You're the best! You saved my weekend, now I can get back to work.