Not sure if this will help much:
PowerBook G3 (M3553):
The PowerBook G3 (M3553) has two different ways to reset the Power Manager. The first is to use the reset button to the left of the Serial port.
Resetting the Power Manager
1. If the computer is on, turn it off.
2. Restart the computer by holding down the reset button to the left of the Serial port for 10 to 20 seconds.
3. If the computer does not restart, repeat step 2 three or four times.
Resetting the Power Manager and PRAM
Resetting the parameter RAM (PRAM) when the computer is shut down also resets Power Manager. The following process resets both the Power Manager and the parameter RAM.
1. If the computer is on, turn it off.
2. Make sure the Caps Lock key is not down.
3. Restart the computer. Immediately after hearing the startup sound, simultaneously press and hold Command-Option-P-R. (If you do not hold down the key combination within 5 to 10 seconds after the computer restarts, you must repeat steps 1-3.)
4. Hold down the keys until you hear the startup sound again. Then release the keys.
5. If the computer shuts itself off, press the reset button on the back of the computer to turn it back on.
6. When the computer has finished starting up, restore any custom settings for the desktop pattern, memory, network, AppleTalk, trackpad, power conservation, and so forth.
PowerBook G3 Series (M4753)
1. If the computer is on, turn it off.
2. Simultaneously press Shift-Fn (function)-Ctrl (control)-Power.
3. Wait 5 seconds.
4. Press the Power button to restart the PowerBook computer.
PowerBook G3 Series (Bronze Keyboard) (M5343)
1. If the computer is on, turn it off.
2. Press and release the reset button on the rear of the computer. The reset button is located between the external video and modem (RJ-11) ports.
3. Wait 5 seconds.
4. Press the Power button to restart the PowerBook computer.
Note: When you reset the power manager, wait at least 5 seconds before pressing the power button to start up the computer. If you do not wait at least 5 seconds, the reset procedure may fail. (If you suspect that the reset procedure has failed, press and release the reset button again and wait 5 seconds before pressing the Power button.)