External Screen Blackout?

I have had the enV Touch since late December and among the various issues that it has, such as  randomly turning off, and the touch screen freezing up, it has now hit a new low. The external LCD screen has gone black. The lights at the bottom 'call' and 'end' keys still respond and light up when I receive a message or call or when I press the unlock button, but the screen is completely black. I can still be in a call with the screen closed and the speaker there works fine, but I just can't see anything! I have tried taking out the battery and leaving the phone off, but nothing has worked so far.
Has this happened to anyone else? And is there a way to fix it?
By the way, the internal screen is working absolutely fine.
Thanks!

I also have had the same problem for about 4 months. (this is my 2nd envtouch). I found out that up near the upper left corner of the screen, near the ear piece, is a sensor to detect when the phone is at your ear. If you quickly put your finger over and then off, the screen will come on. This is most helpful when you need to inter password for voice mail. Hope this helps.

My problem now is the phone will shut itself off randomly.
Brooks