My PowerBook/iBook/MacBook doesn recognize an AC Adapter is plugged into it. Whats going on?
The PMU (or power management unit) in your Apple portable is an integrated circuit in your computer. It’s hardware but it stores settings about your computer. As the name implies, it is responsible for power management of the computer. It controls backlighting, hard disk spin down, sleep and wake, some charging aspects, trackpad control, and some input/output as it relates to the computer sleeping. Over time, the settings in the Power Manager may become unusable, which can result in operational anomalies with the computer. Examples include not turning on, not waking from sleep, not charging the battery, or not seeing the AC Adapter, among others. If your computer isn’t recognizing it’s AC Adapter, try and reset the Power Manager. Click here to view the Apple tech note on how to reset your PMU. If reseting the PMU according to Apple’s directions does not solve your problem, try to disconnect the AC Adapter from the computer and from the wall. Remove the battery from your computer, and l
