User Guide

Mac mini Troubleshooting - 11
Reset the PMU
Reset the PMU with the Top Housing Off
You can also reset the PMU by directly pressing the PMU reset switch located on the logic
board. Follow these steps to access the PMU reset switch on the logic boar
1. Unplug all cables from the computer.
2. Remove the top housing.
3. If necessary, remove the internal frame to access the battery.
4. Measure the voltage of the battery in the battery holder. The battery should measure
2.6V to 3.0V. If the battery does not have minimum voltage, replace the battery. After
replacing the battery, wait 10 seconds and then reset the PMU (refer to the next step).
If the battery voltage is good, go on to the next step.
5. Press the PMU switch on the logic board, located in the rear right corner of the
machine. Be sure to press it just once. Because of the restricted space, you may need
to use a black stick to press this switch.
Warning: Do not press the PMU reset switch a second time because it could
adversely affect the PMU chip.
6. This procedure also resets the computer's PRAM. Be sure to reset your computer's
time, date, and other system parameter settings as necessary.