2964 Views 3 Replies Latest reply: Sep 23, 2008 6:52 PM by spudnuty
The first thing to try is a different keyboard and/or mouse.
Next try this, from the service manual:
"Resetting the PMU (Power Management Unit) on the logic board can resolve many system
problems. Whenever you have a unit that fails to power up, you should follow this procedure
before replacing any modules.
1. Disconnect the power cord.
2. Remove the user access panel from the bottom of the computer.
3. Press the PMU reset switch (shown below) once on the bottom side of the logic board and then proceed
to step 3. Do NOT press the PMU reset switch a second time because it could crash the PMU chip.
4 WAIT ten seconds before connecting the power cord and powering the computer on. If the
computer powers on, go to the next step. If the computer does not power on, there is something
else wrong with the computer, refer to the symptom/cure, “No Power” in this chapter.
5. Run MacTest Pro and return the computer to the customer.
Note: This entire procedure resets the computer’s PRAM. Be sure to reset the computer’s time,
date and other system parameter settings before returning the computer to the customer."
BTW the PMU button us under a rectangular flap of plastic in the user port on the bottom of the iMac. I haven't seen a block diagram on the G4 iMac but the mouse and keyboard are run by the PMU in most other Macs I've seen.
Message was edited by: spudnuty
so that would help my keyboard and mouse problem?
"The first thing to try is a different keyboard and/or mouse"
That's going to tell you if your mouse or keyboard is bad.
"the mouse and keyboard are run by the PMU in most other Macs I've seen."
So resetting the PMU will correct any problem the PMU is having.
Also try another USB port and disconnect any other USB devices or peripherals.