[velocityg4]

I have a g4 800 iMac which appears to be having video problems. When first noticed the screen had over a hundred vertical bars of varying colors. Upon restarting the iMac the screen will flash light across it but never turn on. Before the screen went out the iMac had difficulties waking from sleep. This computer has been brought in for repairs 5 or 6 times but is no longer under warranty. I was wondering if anyone knows if this error would be caused by the motherboard or the video card. Any advice would be helpful.
Note: On restarting drives spin up and the iMac will act as a firewire hard drive.
Has anyone else out there had this many problems with the first line of G4 iMacs. With all the components replaced at service places I was wondering if this model was a lemon.

[Praxis]

I've heard of lines on the screen relating to iBook logic board problems...just a complete guess, but maybe it's a logic board failure?

[velocityg4]

I have performed some tests since my last post.
1. Attached an external monitor to check for a faulty connection to the iMac's screen. The external monitor was unresponsive.
2. Checked wiring inside the case and found no faulty connections.
3. Since the video would not work I recalled that I had file sharing turned on. I gave the iMac ample time to start up and tried to find it on my appletalk network.
4. Blew it away with my shotgun (I wish)
After this and the post from Praxis I am forced to conclude this is a faulty logicboard. If anyone who is certain this is a case please let me know. Also does anyone know how much one of these boards would cost to replace?