Snes New 3DS XL

I don’t know if I’m posting to the right place but I need help fixing my ds. My x button started to only work when you press really hard on it, so I looked up online for a fix and it said to take it apart and clean the insides of the buttons. I’m used to doing this kind of stuff, so I don’t think I messed up anything taking it apart, but when I put it back together it wouldn’t turn on. The charger works and the battery does too, but it just won’t turn on. The blue light doesn’t show at all when I press the power button, and I know it worked last night (that’s then the x button died). Please help!