Resetting display settings in Lion

henrik · **Posted:** Mon Dec 12, 2011 10:20 am

I very recently moved and decided to tough it out for a while with just my laptop until I get my things in order and have room for the desktop. But I decided to attach an external monitor to it to enhance my experience a little. While I was playing around with the possibilities (as I've never had a mac with dual displays before), I hit the button that said "mirror displays" to see what it did.

Unfortunately the button in my case actually meant "brake everything!" and I was left with two monitors filled with graphic jumble. The problem persisted even though I booted because the system obviously remembers the setting. I can use the machine when I detach the other display and reboot, but when I connect the external display, they both return to the graphic jumble again.

So is there a way to completely reset my display settings so that the system would forget about the other display and I could start again from scratch?

Iggy · **Joined:** Wed Mar 16, 2005 2:37 pm **Posts:** 816

does simply pressing the button again not fix it?

if not reset the SMC

Reset the SMC of a MacBook or MacBook Pro’s with detachable batteries:
* Shutdown the MacBook/Pro and remove the battery
* Disconnect the power adapter, hold the Power Key for 10 seconds
* Release the power key and reconnect your battery and power adapter
* Turn your Mac on
* Let boot as usual.

Reset SMC of a MacBook or MacBook Pro’s with an internal battery:
* Shutdown your MacBook/Pro
* Connect the power adapter to your Mac
* On the MacBook/Pro’s keyboard, hold down the Shift+Control+Option keys and the Power button at the same time
* Release all keys and the power button at the same time
* Boot your Mac as usual

henrik · **Posted:** Tue Dec 13, 2011 10:26 am

Pressing the button again was impossible because the screen was filled with nothing but jumble.

Unfortunately I followed some other advice first. It included deleting some windowserver plists and it rendered the operating system unbootable. I had to rebuild the system from scratch, which was a bit of a hassle because I had to install Snow Leopard first to create a bootable Lion USB drive.

Well, no matter, the issue is now resolved and a little system cleanup never hurt anybody.