i have a question for you guys. recently my pismo was exposed to some coffee spill (a BAD thing) and now it´s dead. but it seems to me like the only thing damaged is the pismos modem. i wonder if a fresh modem will bring life to my pismo, so my question is:

will a bad modem stop a powerbook from working/booting at all?

A bad motherboard will stop the machine from working. So will a shorted out battery. Did you try plugging it into an outlet to test it out?