http://www.zshare.net/download/powerbookg4-mp4.html Hi, i got a big problem with my powerbook g4. The screen begins to flicker, than it freezes and then it goes off. It's documented in the video, i hope you can watch it, it's encoded with quicktime 7 using the h264 codec. This problem appears randomly and when the screen goes off the system is still fully functional with an external screen attached to the pb. the screen is black but its backlightning is still there (you can still adjust the brightness for example). The problem first appeared about 4 months ago, so i went to an apple shop and they said that it's probably the monitor cable. sadly i couldn't show the problem to them because of it's random nature. so they sent it to an apple repair centre. 3 weeks later it came back, apple did nothing because they couldn't find the problem. obviously i wasn't very happy about that and about two month later the problem was back in full effect. i could hardly work with the pb because display almost always went off so i decided to capture the damn thing with my video camera (should've done that earlier i know). I went to another Apple shop with repair service in the store. i showed them the video and they said that it's probably the mainboard . So i gave it to them. 5 days later they called me and said that they couldn't find any problem, sorry . So here I am only 1.5 month warranty left. Maybe you could help me.