Dead hard drive. You can boot from the os x DVD that came with the computer (by holding down the c key immediately after the start tone) and run disk utility to see if it can be repaired. If that fails just replace the drive and reinstall. Its a bit of surgery to replace in that model but its doable.
Thanks for the reply, To be honest i'm looking to sell it (as i've got a new macbook pro) and the buyer wanted to know if this was a problem caused by a faulty logic/motherboard, ('cos of the lines across the screen), do you think that can be ruled out then?
Thanks for the reply, To be honest i'm looking to sell it (as i've got a new macbook pro) and the buyer wanted to know if this was a problem caused by a faulty logic/motherboard, ('cos of the lines across the screen), do you think that can be ruled out then?