Re-booting problems in Powerbook G4

[Otilio]

I have a Powerbook G4 series which i have been using for a while now. It has OS X snow leopard installed in it. The problem i am facing is whenever i try to re-boot my mac, it shuts down. When the system is rebooted, the fan starts but there is no start up chime. This continues for about 5 secs and the system shuts down with a loud beep. After attempting to reboot many times the system boots once. Please suggest some solution about the issue.

[Rawko]

By looking at the problem it seems like you will need to do a PMU (Power Management unit) Reset. To perform PMU reset, first shut down the powerbook and remove it from the power source. Now locate the button for PMU reset whose location is given in the Apple handbook. Mostly the PMU reset button is placed at the side between the ethernet port and video card. Once you locate this button , press it and hold it for 5 secs. Now release the button and let the computer sit for 30 seconds and then start the computer.

[Hardwareman]

You need to replace your PRAM get the system working. As soon as any system starts , it first tries to access it RAM. When it is not able to find it, it indicates it by beeping. May be there is a layer of moisture which is set on the PRAM and is making it inaccessible to the system. Take it to the apple service center and get the PRAM checked. I think replacing the PRAM will definitely solve the issue.

[RoninBlade]

Before replacing the PRAM on your system try to reset the PRAM. PRAM can be reset as follows.
Power down the computer (Disconnect it from Power Supply)
Press the following keys and keep them holding "Command, Option, P, and R."
Now press the power button and start the computer. A gray screen will appear and the system will restart. Keep holding the keys down till you hear the start-up sound for the 2nd time. When you hear the start-up sound for the second time, release the keys. This will reset the PRAM and will hopefully solve your problem.

[Killen]

The battery on the logic board is the root cause of your problem. Open the powerbook if you can and remove the battery which is there on the logic board. Check the voltage across the battery using a Multimeter. The voltage across the battery should be around 2.5 to 2 Volts. If the voltage is less than 2 volts then get a new battery and put it in the logic board. Once the battery is replaced, remove the main battery. Now press the power and hold the power button for 30 seconds and then release it. Now put the battery back in and start the system.

[deoWo]

G4 series of the Powerbook has lots of problems with the logic boards. As your system is giving a loud beep and shutting down, the problem certainly is with logic board. Take your Powerbook to nearest apple service center and get the logic board checked. Replacing the logic board is the only solution to your problem. If your Powerbook is still under warranty then you will get the logic board replaced for free but if it is out of warranty cover then you will have to pay for the parts replaced along with there servicing charges.