XPS 15 9550 will not post or boot

So I let my sister use my laptop, she left it on but put it in a sleeve/case and it overheated like crazy because the fans started spinning to cool it down but there was no air to move around in the sleeve so it only got hotter and hotter.  Afterwards, it worked completely fine still, but now a week later, it will not run on at all.

The light on the power button is always on, the laptop makes no noise at all, nothing shows on the screen, and when I press or hold the button for 30-60 seconds nothing happens.  No matter what, the laptop shows no sign of life except the power button light.  Nothing turns on in the laptop and the light on the power button is always on. Power + d does nothing.  The only time the light turns off is when I unplug the battery and unplug the charger too (the light will stay on when the charger is plugged in even when the battery is unplugged).  I am thinking the battery is fried, but I do not see anything visibly wrong, corroded or burnt.  Please share anything that might help. Thank you!

Edit: Possibly stuck in sleep mode? Also, the charging light under the trackpad on the front never turns on when plugged in.