A PowerBook G4 can develop a corruption in the system file controlling the date and time functions. This will cause the G4 to behave erratically, and it must be fixed. Reset the G4's parameter RAM setting (PRAM) to fix the date and time functions. A few key commands are all that is needed---no special programs or expertise with the G4's operating system are needed. The procedure is straightforward and works in an identical fashion, regardless of which model of PowerBook G4 you have.
Press and hold down the PowerBook G4's power button until the LCD screen goes black---the power button is at the upper right corner of the keyboard.
Press and hold down the following keys together with the fingers of one hand: "Command," "Option," "P" and "R."
Press the power button once to turn the PowerBook G4 on.
Wait for the start-up sound to go off twice. Release the keys so that the PowerBook G4 can boot to the desktop with a new date and time system file that is not corrupted.
You will need to set the correct date and time for the G4 after it has been reset.