Power button issues, unplug flex cable and tablet turns on.

This is my child's tablet so it's a little used and abused. But it flips back and forth between a black screen and the Samsung galaxy tab3 screen, that comes up when turning on. Now the power button is not actually stuck but it's acting like it is. I took it apart and unplugged the power flex cable and it started but the touch screen does not work, if i plug it back in, it turns off. So if i get a new flex cable would that solve the problem? Or you think thats more the motherboard connector? I would like this to be fixed soon but don't have the money to be guessing on the problem.