Phone dies randomly, won't turn on or charge

[Thasausbaus]

So nothing bad happened to my Galaxy S4 Mini, no water or fall damage or anything. It just randomly stopped working.
The screen is black all of the time, holding the power button doesn't do anything, power + volume up/down + home button doesn't do anything, while a charger is plugged in, the LED doesn't light up, nothing.
I've also tried NordicNinja's tactic here: https://forums.androidcentral.com/verizon-galaxy-nexus-rooting-roms-hacks/144633-phone-died-wont-charge.html
Also, the battery looks perfect on the outside, it doesn't "spin"

Is there something else I can do or is all I can do test a new battery?

 

[B. Diddy]

Welcome to Android Central! Batteries can fail at any time, and they don't have to swell up. If that's the original battery on your quite old phone, then it would not be surprising if it had died. Try a new or different battery.