Power Button light on, laptop not turning on

The laptop was left untouched on a table no one uses for about 2 weeks (so no environmental issues, and it's used lightly with a vinyl cut machine program). I went to turn it on, and the power button did not blink/turn on. I plugged the laptop into the charger, and the power button lit up immediately. However, the laptop does nothing else. There is no sound of it turning on, no blinking lights, no screen light whatsoever. Just the power button light steady on.

I've removed the back cover, removed the battery, held the power button in for 30+ seconds, reinstalled battery & back cover, no change. As soon as the power adapter is plugged in, the power button light immediately turns on and nothing additional happens.

Any ideas?