3DS not turning on? charging problem

Okay my sons have 2 separate Nintendo 3ds xl. (Not new ones). My daughter has an old one too. I have tested my sons batteries in my daughters worming 3ds xl.

They are 100% charged. However when I try to turn on my sons it doesnt do anything. No blue power light. I plug in thr charger it lights up orange to say the charger is in the system. Please help. I have checked ribbons, popped off Wi-Fi card and put it back in place. Also the charger port is not lose or wiggly, its still in place. The only thing is, when you plug in the charger cord into the unit it doesnt fit snug like it use to. It is kind of loose. Pleased help in going out if my mind trying to figure This out.