I posted this awhile back, but didn't find a solution... Anyway, my 12" PowerBook G4 is back from the shop, where, I found out, they haven't worked on it for three weeks or so (it's been there two months!)! It still will not boot. The battery charges, and when I press the power button, I can hear the "click" noise that means it's trying to start. I can never hear the HD spin all of the way up. It sounds like it tries and then fails. Nothing ever appears on the screen... ever. I have to do a hard shut down, and then it sounds like the HD spins down. Ideas? For awhile, it did the "double dinging" noise, but I don't know what that means... and couldn't find anything on support.apple.com about it. I would really like to have this working again! Thanks.