Frances,
Your friend probably has the Powerbook G3 FireWire M7572, a.k.a. Pismo.
http://docs.info.apple.com/article.html?artnum=24604
What often happens when a powerbook is stored for any length of time is the power manager becomes corrupted and a normal power manager reset will not correct the issue. There is a simple fix, however.
- Remove the main battery, optical drive module, and disconnect the power adapter. Place a support behind the display so the 'book does not tip backwards.
- Lift off the keyboard and lay it face down on the palm rest; do not disconnect the keyboard ribbon cable.
- You will see two round, brown batteries in a black case between the HD and palm rest...these are the internal rechargeable backup batteries a.k.a. PRAM batteries. You will also see a red/white/black pigtail wire running from these batteries to the logic board. With a pair of needlenose pliers, carefully disconnect this wire from the logic board (pull up on the white connector).
- Now connect just the power adapter and try starting up; if successful, press/hold the power button until it shuts down. Remove the power adapter, reconnect the wire, then plug in the power adapter and try starting again. If no start, disconnect the PRAM batteries and leave disconnected until you get a replacement; the batteries have failed and probably have an internal short which is preventing startup. You can reassemble the 'book at this point and use the powerbook until you get a replacement battery. It will run fine without this battery.
- If the 'book will start with the PRAM batteries reconnected, reassemble the 'book and you should be OK.
After you lift off the keyboard, this is what you will see (enlarge bottom picture):
http://www.ifixit.com/Guide/Mac/PowerBook-G3-Pismo/Keyboard-Page-1-Keyboard
If the main batteries have been left discharged for 6 years, they will be shot. The PRAM batteries can easily be replaced if needed; they are rechargeable but again, the discharged state may have killed them. You can test them after following these instructions:
http://docs.info.apple.com/article.html?artnum=30580
You can find batteries at many vendors, but here is a very good company:
http://eshop.macsales.com/shop/batteries/
You can also run the latest version of OSX, 10.4.9, very nicely on this machine with additional memory and possibly a larger HD.