g4 won't boot

hey everybody
i'm a newbie and would like to say thanks for the cool site. now here is my delema. i have a g4/400 bumped to 133 mhz single, os 10.41. it worked fine until i accidently pulled the external firewire (while running) and now i can't boot up. not even from an external drive. i was in the process of doing some disk maintenance and was informed by disk utilities that my internal cd rom had some bad blocks. that is when the accident took place. now, when i try to start up the cpu it turns on, the apple screen appears, while the loading icon wheel spins for a couple of min. and then the computer shuts down completely. i've tried holding down the c button (during start-up) with the system install cd in the internal cd rom (didn't work) also tried with external usb drive (didn't work) it won't start-up on any of my emergency software either (norton utillies, techtool) what is my next step?
no cash for klunkers jokes please i really need help