27" Cinema Display, no picture since 10.8.2

Been searching around for answer to this for the last few days:

I have a 2010 27" Cinema Display that will not show picture when connected to any machine (i've tried a 15" MBP, a 17" MBP and a 11" MBA with via mini display/thunderbolt port) running Mtn Lion. However when connected to another MBP pro running 10.6.8 the display function perfectly.

I've tried multiple smc resets and PRAM zaps. NADA. I've tried safe mode boots and recover partition boots.Nothing. I've tried muitiple startup arrangements and feel i can rule out a handshake problem.

Called apple today and spent about 30 mins running through there troubleshooting list (which meant i tried the above all over again) and ended the call after the tech on the other side told me he was stumped. I'm out of warranty and it seems without a paddle.

So now i'm coming here to you all in the hope of some insight or inspiration.

Thank You

Just a long shot:

Open the Displays System Pref pane and hold down the Option key. The Gather Windows button in the bottom right of the window should change to Detect Displays. Try clicking that.

If that doesn't work, shut down your MBP, then disconnect the display from your MBP and unplug the display from the wall. Reconnect the display to your MBP and boot the MBP, leaving the display turned off. When your computer is showing the desktop with everything connected (external drives, network etc.) plug the display back into the wall outlet. Wait a few seconds and see if your MBP recognizes the display. If not, try the Display prefs trick again.

Good luck.

Sorry i realize now i left some details out:

Thanks for the response lightcraftsman. I have tried both of those solutions but to no avail.
Thing is the display shows up in the display menu of system prefs, i can detect displays, gather windows, adjust brightness the whole nine, but i get no image. Even the screens backlight remains off and at first i thought this was a hardware failure except that it functions perfectly when connected to my macbook pro running 10.6.8

Gotta ask. You have updated the software on your computers running Mountain Lion, right?

yeah OS is fully up to date

I thought so.

I'm stumped. I suggest you call or email Apple Customer Relations and find a supervisor who can escalate this to Continuation Engineering. Sounds like a bug in the OS.

Send me a PM if you have trouble finding a contact.

So, the 3 machines are Thunderbolt and your 10.6.8 machine is Mini-display correct? I had to apply a firmware update to my 24" to get it to work correctly with Thunderbolt and Lion / Mountain Lion.

Just a thought...G/L

Actually only the one macbook air i tried is thunderbolt the MBPs are all mini display port, so i've tried two minidisplay port machines running 10.8 with no luck. Also tried a MBAir running 10.7.4 today with no luck.