OS X 10.4 won't Startup

Please help,

I have a 3 year old iMac (non Intel) and I just tried to restart it. On reboot, it does not get passed the Startup screen, with the scrolling blue/white bar. It gets to the very end of that, where is says "Starting up Mac OS X" and then stops.

Any idea why this is happening or how I can fix it?

Thanks

First off try zapping the PRAM by rebooting and holding down immediately after the chime the Command (with apple logo on it), Option P and R all at the same time and keep held down until third chime, release and see if the machine will boot.

If no joy try booting from the install DVD by holding down 'C' immediately after restart. If it starts run Repair Disk from Utilities whilst booted from the disc.

Keep us posted?

What happened prior to u experiencing this issues? the above fix should be able to help u. However it may be helpful if you can tell us what happened before it let to a non-boot system. It may be fonts that's causing it or start-up items. You can boot into safe boot by holding into shift after pressing the power button from a shutdown mode.

I wound up re-booting with the Install disc and everything seems ok now.

thanks for your help!

Did you run Repair Disk whilst booted from the startup disc and what was the result as if it is a HDD problem may well recur?

I ran the Disk Utility while the Install Disc was in, but nothing came up.

Seems very strange... its running fine now though. I ran the Install disc to save all of my files (I did not erase all and install), so everything was still there once I started up. I just had to re-install a couple of extra programs I had on there.

It just kinda happened out of no where. I wasn't running anything different than usual, nothing like that.