My iBook G4 is refusing to turn on. Yesterday it started going really slow and pressing the power button wasn't bringing up the usual options, so I held the power button to switch it off. On turning it back on it got stuck on the screen with the Apple logo and spinner for a long time so again I powered it off with the holding of the button. I then let it cool down (it was really hot) but now when I switch it on the spinner spins around 6 times then it turns itself off. It is still chiming. I'm away from home and don't have any discs - anything I can try or is it time for the Genius bar? Any help much appreciated.