It happened to me like 1 year ago, at the beginig was 6-8 lines, now half of the screen is black and white, no more lines because they grow very fast, and in the other half there is a lot of lines.

I have found no solution, but I still use it, I also have a MBP, so I always go to the option share screen.

[quote|Mago]It happened to me like 1 year ago, at the beginig was 6-8 lines, now half of the screen is black and white, no more lines because they grow very fast, and in the other half there is a lot of lines. I have found no solution, but I still use it, I also have a MBP, so I always go to the option share screen.[/quote]

Sounds like your LCD panel is going bad. You can verify it is only the panel by connecting an external monitor to the unit - if it looks bad as well, then the graphics processor on the logic board has gone bad. If you are near an Apple Store, the Genius Bar can help isolate the issue for you for free if you don't have an extra monitor.

Unfortunately, the LCD and the MLB are the most expensive parts of this model, and due to its age I'm sure its no longer under AppleCare. If it works properly on the external display, that might be the least expensive option.

[quote|David Iwanicki]Sounds like your LCD panel is going bad. You can verify it is only the panel by connecting an external monitor to the unit - if it looks bad as well, then the graphics processor on the logic board has gone bad. If you are near an Apple Store, the Genius Bar can help isolate the issue for you for free if you don't have an extra monitor. Unfortunately, the LCD and the MLB are the most expensive parts of this model, and due to its age I'm sure its no longer under AppleCare. If it works properly on the external display, that might be the least expensive option.[/quote]

Look here [http://www.mac-pro.com/Mac-Pro-Online-Store/G4-iMac-Parts-Flat-Panel-700Mhz-800Mhz} for a diagram, you can replace the LCD screen yourself (it is labor intensive) but if your time is your own you can resurrect an otherwise good machine for a few hundred dollars and some time.

Good Luck,

N.

[quote|machead3]'''Look here [http://www.mac-pro.com/Mac-Pro-Online-Store/G4-iMac-Parts-Flat-Panel-700Mhz-800Mhz} for a diagram,''' ''you can replace the LCD screen yourself'' (it is labor intensive) but if your time is your own you can resurrect an otherwise good machine for a few hundred dollars and some time. Good Luck, N.[/quote]