I've got a summer job at an IT repair centre, we mainly fix virus-ridden toshitbas and HP's with broken screens. Anyway, basically I found a broken macbook amongst all the junk as I was tidying up. I asked if I could take it home to have a go at repairing it (on my own time - it was headed for the bin). So it's clearly got issues. This is how it goes: Pressing the power button boots the machine, there's the grey apple and after some time a blue screen. It then switches between the blue screen and a blue screen with a little spinner, endlessly. I can hold alt and get into boot options but it must be too old to have the Apple HW test built in - so I can't run that. I don't the have install media, I only have a 10.4 disk, and a 10.8 bootable usb. It doesn't boot from a windows bootable CD either. Any ideas on what to try next?