The WSoD is an LCD driver chip failure that usually happens early in the life of the 770, although there have been some occasions of people getting it a year later on units, but those seem to be rare. In general the problem occurs after doing a cold shut down and reboot of the unit and usually appears early on somewhere between 10th to 20th reboot.

Clearly, because these units are based on Linux there is no real reason to shut down the unit and the only time I ever have to reboot my 770 is because the battery went dead on me.

If the person you are getting it from has had it for awhile they you are probably okay. I had 2 WSoD within 2 weeks when I first bought my 770, but over a year later (knock on wood) my 3rd 770 has been flawless.

If your not buying the unit and the person you're getting it from has had it for awhile, then you'll probably be in good shape.