3DS won't turn on, but says the battery is at 100%

The power light won't turn on much, and when it *does*, it flickers. Most of the time it won't turn on at all unless it's on the charger. Rarely, the device will "turn on" and then a second or two after, it turns off.

The one time I have seen the device turn on fully before it shut itself off, the battery icon was full. Which is weird because it won't turn on most of the time/ at all if not plugged in

The charging light also flickers, and I know the charger works, I tested it on a different system.

I'm not sure if it matters but the 3ds is modded.