Q: mac powerbook g3 series will not start up fully

I recently got a Mac Powerbook g3 series 333MHz/512k cache/64MB/4GB HD/8MB Video/CD I have no idea what the operating system is.

It was a gift to my son from his gramma as he loved to play on it. however now will not fully start.

When you power on you here the startup  tone thena white screen with the apple in the center, it will not go any farther.

I am not mac savvy so any help to get it going for my little boy would be greatly appreciated.

I know its an old laptop & i should just get him a new one but he really loves this mac.