On power adapters, PMUs and the new PowerBooks
As I was using my one month old PowerBook yesterday, I was alarmed to see the charging light on the power adapter randomly shift between orange and green. I came up empty handed after some googling and searching Apple's Support pages, so I started plugging the adapter into other outlets in the apartment. No go; my adapter was still putting on its own little glowstick show for me. I then decided to look up Apple's support document detailing the procedure for resetting a PowerBook's PMU (Power Management Unit), which brings me to the first lesson I learned: Apple changed the PMU reset procedure for the most recent 15" and 17" Dual Layer SD PowerBooks, so definitely check it out if you go down this same road.
Unfortunately, a PMU reset still didn't solve my dilemma. Getting nervous, I finally decided to take advantage of Apple's insulting "90 days of complementary support" to see if they could bail me out. Fortunately, after some troubleshooting, I learned my second lesson of the day: PowerBook and iBook adapters, if left plugged into a wall for too long, might need to actually be reset. This can easily be done by unplugging both of an adapter's ends for at least 60 seconds. We didn't delve into the inner workings of these power adapters for an explanation, but I've kept one plugged into a specific outlet in my apartment for probably at least a month or two, and I guess that might be just enough to make a power adapter a little confused in the head. So kids, remember: don't be like me. Keep your power adapter happy and light-show free by unplugging it from time to time.
