[LaurenD]

I've been running two monitors for some time, with no problems (the external monitor is an older Dell 15" flatscreen). Now, I get vertical artifacts against a black background on the external monitor, but the cursor (arrow) is showing on top of the black.

IF I PLUG IT IN AFTER BOOTING: Both screens go to black with a white vertical line or two.

IF I BOOT WITH EXTERNAL MONITOR ALREADY PLUGGED IN: Only external monitor powers up, as usual, but after a moment of clear blue screen, it goes to black screen with vertical lines again.

Either way, the curser still shows, and I can click around at the top of the screen and it seems to be doing something (though I can't see what it's doing, i can hear a volume change when i get lucky enough to hit the right icon).

It seems to me this might be some kind of resolution-change issue, but then why would it effect BOTH monitors once the external monitor is plugged in.

Any suggestions?

- Lauren D in SC

[stanm88]

I've got the same issue.

[Arcady]

It sounds like you turned on mirroring. See this thread.

If so, use these instructions (copied from the thread linked above):

-Open up Terminal
-Type (minus the " ") "mirroring off" and DON'T hit enter
-Plug in the VGA cable, and if it gets garbled, hit enter and wait a few seconds, your extended desktop should be back.

[belfastbiker]

Originally Posted by Arcady

It sounds like you turned on mirroring. See this thread.

If so, use these instructions (copied from the thread linked above):

-Open up Terminal
-Type (minus the " ") "mirroring off" and DON'T hit enter
-Plug in the VGA cable, and if it gets garbled, hit enter and wait a few seconds, your extended desktop should be back.

Worked a treat - External monitor working beautiful with ful-size iWeb!

Of course, it highlights how AWFUL my old CRT 21" was, compared to my sublime 9" mini LCD.

Time for another purchase, or a switcher maybe....

[ssd]

It happens to me when I plug to a 2nd monitor that doesn't have the resolution/frequency that I used in the first monitor. But mirroring trick works.