Hey - This post is a duplicate of my post at the apple support forum - trying to see if anyone else has had similar experiences and can give me any help whatsoever... --------- Hi there - I got my MBP back today, after having the logic board replaced to resolve the nvidea graphics card issue (http://support.apple.com/kb/TS2377). After working with it for about 40 minutes the screen went blank. I ran the Apple Hardware test on restarting, and got the following error code - 4SNS/1/4000000:TGOD I've given it back to the guys who repaired it for further testing. They said that their diagnostics arent showing anything, but the Apple Hardware Test has come back with this error each time. I've searched around for information on this error, and there are suggestions ranging from issues with the logic board to a thermal sensor issue. I've found 2 threads in this forum where people have experienced the same sequence of events - logic board replaced for the nvidea problem, only to get this error code when the laptop is returned. http://discussions.apple.com/thread.jspa?messageID=8633584� http://discussions.apple.com/thread.jspa?threadID=1850653&tstart=0 Can anyone shed any light on what the problem might be? Has anyone else had the same issue? Any feedback would be appreciated.