Death of a mac?

Defo a hardware problem IMO.

Could be video card/chip, LVDS cable, video port, display, etc.

You can troubleshoot to narrow it down, then work out whether you want to front the cash for a fix depending on what it is.

Troubleshoot Q1: Do the pixel lines appear when using an external display?

Yep, I always use an external display here, i only use as a laptop when I'm away or going to meetings etc.

I actually think it's a problem with OpenGL or whatever it is Leopard uses to render, because earlier i rebooted, and it was fine for a bit, then I went to the desktop, and it had a line across it, if I brought an application over the top of it, then moved it away, the line was still there, but if i moved icons about on the desktop, it re-drew it and cleared the line (or made another elsewhere). So I'm thinking it's the 3d chip on the GFX board. balls.