Display on MBP and Thunderbolt Display

I have a MBP connected to a Thunderbolt Display (TD) and had no problem until a few days ago. Now whenever they are connected both screens are blank. The MBP works fine and the display is okay for as long as it is not connected to the TD. The TD is okay as I have checked it with another MBP. What could be wrong? Settings on the MBP? I need help!!

Have you tried the MBP with a different Thunderbolt Display? (It could be the Thunderbolt connection on the MBP) Yeah I know - everyone has spare TB displays lying around - but you could take it to the Apple Store and see if they could hook it up and test the TB port.

The other thing you could try is hooking up a regular display through an adapter - try HDMI or DVI if you have those adapters handy.

Ivan - Thanks a lot. Yes I've tried with a different Thunderbolt Display and both still blank. I have also tried a different MBP with my Thunderbolt Display and they were okay. Today the Thunderbolt Display worked fine when I closed the MBP.

Generally - Apple is pretty good about not allowing you to go out of range of available monitors - but since closing the MBP at least brought something up - then it may be at some point - you put it in a mode where the MBP cannot display to the dual monitors. I guess one thing to try is to hook it up to the TB display, close the laptop. Connect an external keyboard/mouse - then open System Preferences -> Display. Try setting the mirroring checkbox - and opening the MBP. See if it will at least come back and mirror on both displays.

Also check Accessibility -> Display and Accessibility -> Zoom - maybe it got into one of those modes.

Maybe also check that brightness isn't set all the way down when connected - you could try hitting f2 (or fn-f2 if you have it setup that way) and see if that helps.

Just tried the mirroring checkbox and opened the MBP and that did not work.

Also checked the Accessibility and the brightness and it is neither.

Sad thing is that I am far (in Lagos Nigeria) away from any Apple Store.