Brownish screen

[AndrasK]

Hi All,
I have recently purchased a refurbished T60. What I observed, is that every once in a while the screen goes blank, with a brownish color, and keys stop working. It looks like everything is running in the background however (i.e. movie still plays). All I could do was close the lid, wait for the machine to enter sleep mode, then power it up again by opening up the lcd. Then it worked. I do have return guarantee for my T60, but I wonder, what could be the problem?
Any ideas?

thx,
Andras