A hot MacBook Pro, short battery life, and a PMU (power management unit)
My MacBook Pro is giving me some cause for concern again.
The battery, which was replaced in July after an ‘expanding battery’ incident, doesn’t seem to last very long. The maximum running time from a fully charged battery had dropped from 3.5 hours to less than 2 (some times only an hour or so). This was odd. I also noticed that the machine was running very very hot.
I had tried all the usual tricks. Battery setting to ‘better’. Turning off ‘Airport’ and not playing iTunes, but to no effect. Plus, the machine was running even hotter than normal when the power supply was connected.
A thought then occurred to me (an increasingly rare event these days) – may be there is a PMU (power management unit) problem? Therefore I decided to reset the PMU.
How to reset the PMU on a MacBook Pro:
- Turn off the computer.
- Disconnect the power supply.
- Remove the battery.
- Hold down the power-on button for 5 seconds.
- Replace the battery.
- Reconnect the power supply.
- Restart the machine.
So far, so good. The machine appears to be running cooler when the power supply is connected (and on battery) and I seem to be getting better battery life.
