iPhone boots up then back down
So I got a iPhone 5 here with some issues. Soo when I power on my iPhone, it displays the apple logo and then stays for 10 seconds intill it power down. It sits like that unless I press the power button again and it does this same process again. I decided that maybe it was the battery, so I changed the battery and the same thing happens. I decide to take my other iphone (another iphone 5)and test the replacement battery, the other iphone is on 100% , showing no signs of faulty battery. I then try to charge the phone with no battery to check if it was the blogic board or sum, and still the same issue happens. I try to set this iphone in Recovery mode and DFu mode but two problems are present. 1.) for some reason the square button acts inactive, even though its a good square button. 2.) When plugged into the computer, the computer doesnt connect. I checked different wires and everything, but nnothing seems to work. Can some one please tell me whats wrong with the iphone, if its a common/uncommon problem, and if it can be fixe. Thank you
Is this a good question?