Laptop screen goes dark when unplugged
Hi
This has gradually become more of an issue in the last few months.
My laptop is plugged in most of the time, but now, when I unplug it (and the battery is at 100%) the screen goes dark after just a few minutes (to as little as less than a minute).
MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports)
Processor 2.3 GHz Intel Core i5
High Sierra 10.13.6
The machine is about 3 years old.
Anyone have an idea of what might be causing this or any diagnostics I can try?
thanks