help!, i have a powerbook g4 1.67 that was working fine last night, but won't startup this morning. it wasn't moved or dropped. when i push the power button i get the tone and the optical drive does it's noise like it's trying to unload a cd, then it just keeps making the noise every 2-3 seconds. the LED sort of dims or blinks at random. so i hold the power button down until it shuts off, then try to start it again, this time i may or may not get the tone. the OD just starts cycling again. i reset the PMU which made the LED shine constantly at least, but didn't seem to change anything else, tried to reset the PRAM, but i don't know if that actually worked. i don't think there have been any symptoms to indicate any trouble, it's been working well every day. so what can i do next?
WB
WB