Macbook pro goes black with keyboard lit ?????

Macbook pro goes black with Apple Laptop Keyboard lit ?????



please help, my mac book goes all of a sudden straight to black screen, but the keyboard is still lit.



is this a mother board problem? (I have been there, done that and bought the bloody t-shirt) so I hope not.



The funny thing is, yesterday across the table form me, sits my girlfriend with the same macbook pro.



at the same point in time, BOTH MAC'S went to BLACK! ???



I have just upgraded to LION, but this was going on before that, but much more ERATIC now!!



My Girlfriend has never had Apple Laptop Keyboard happen to her macbook pro before. so that might be a lion thing.



and, I have always a 500GB G-THEC harddrive plugged in using iPhoto and iTunes .



( last night I moved iPhoto and iTunes over on my macbook pro, but still happening.



please help.



ps. at times I also use a apple 27inch screen/monitor LED/Apple Laptop Keyboard .