[olpc-help] OLPC will not complete boot up

[gdbry]

Hi,

When I try to boot, the computer lights up, plays a couple of notes on the speaker, the shows the XO with one dot under it.   It locks up there.

If I hold the "O" on the game controller while starting it says:

Release game key to continue

Boot failed 
Powering off in 10 seconds

This started when the computer seemed to lock up loading a pdf file and I took the battery out to reboot it.  

I hope someone can help.

George