For several months now, the light on my power adapter for my MacBook Pro (mid 2009 13", OSX 10.11.6) has been unreliable. The light may be off, but the machine will still be running on the adapter power and charging its battery. Resetting the SMC does not affect this. Sometimes jiggling the power adapter connection to the power port or unplugging the power adapter and rotating it 180 degrees before replugging will bring the light back.
This weekend, some new behaviors started. One time the power adapter was connected, the light on, and the machine running on the adapter, but the depleted battery was not charging. Once the machine was off, adapter connected and battery charging, when slowly, over about 30 seconds, the adapter light faded out and the battery stopped charging. Several times the adapter was connected with no light and the machine reporting running on battery. Very patient jiggling or plugging and unplugging of the connection to the power port ultimately seemed to cure each of these problems.
On one occasion, upon starting the machine, the adapter battery began blinking. I unplugged the adapter, reset the SMC, and tried again, and the blinking behavior stopped, but with the intermittent nature of these problems, I really can't say if the reset was the cure.
Now if I leave the machine unattended I can't be sure it will continue to draw power from the adapter. When I return I may find the light off and the machine drawing on its battery.
The machine has a non-Apple replacement battery that I installed 15 months ago. The system reports that its condition is good and its capacity still close to 100%.
Do I need a new adapter? A new power port? Some new internal electronics? Is there a visit to the genius bar in my future?
MacBook Pro (13-inch Mid 2009), OS X El Capitan (10.11.6)
