It's been working beautifully, but suddenly it's running on battery power and is dangerously low. I plug it in but it stays on battery power. Is my power supply gone bad? It's about a year old but was used a LOT. Is there a way to test the power adaptor?
Good or bad power supply, it could be an indicator problem.
Attach to house power and see what happens; it's going to run down sooner or later no matter what you do if something is malfunctioning. At least this way you'll know as early as possible if something is broken.
If you have a compatible Apple device you can test on it; or a buddy's Mac. If you have a multimeter you can check voltage from the charger with it.
It does sound like a mechanical problem, as opposed to a software problem, and the ultimate evaluation there is to get it to Apple.
Good grief! Nevermind. I was plugged into the wrong cable. One that wasn't plugged into a power adaptor... sorry.
Macbook Pro won't switch from battery to power supply
