Why isn't my phone turning on

So i have a unused samsung galaxy s 5 mini and i wanted to see if it works (it was unused for about a year), well it didn’t even turn on, so i thought: ok let’s charge it and try agaim later, i put it on the charger the red light signalizing it’s charging was turned on i came back an hour larer and tried to trun it on, but it didn’t work and the red charging light was still on (i tried to take the battery out and i’ve read through a lot of troubleshooting websites and still nothing) . So what’s wrong with it?