Lines on display came and went
Here's a weird one.
Have an old Macbook Pro from 2006, Core 2 Duo 2.16 with 3GB RAM.
I'd shelved it maybe 2 years ago because it suddenly developed horizontal lines on the display that appeared AFTER the computer had booted into the OS, which was Lion.
During boot there were no lines.
Well, I just pulled it down off the shelf to check it out for parts. Decided to plug it in and see what, if anything worked. I only had an external disk on hand, with Snow Leopard. I booted from that and got the horizontal lines. Shut down.
I had another external disk on the desk, with the Mac Post Factor Mountain Lion installer, which I'd recently used to install ML on a MB Pro 2006 2.33, which works fine.
I booted the 2.16 MB Pro from the installer disk and it booted fine, and Macpostfactor asked me where I wanted to install Mountain Lion. There was no internal HD in the computer, so I connected a formatted 2.5" disk via USB and installed Mountain Lion to that.
I then booted from that external disk with Mountain Lion and it booted fine, BUT NO HORIZONTAL LINES! Weird. So now I'm checking out the computer, running off the external disk, and everything works fine. Wifi, iSight, USB, keyboard, trackpad, etc.
Anyhow, I'll install the disk in the MB Pro and try to run Mountain Lion from that.