If you look very carefully the edge of the rear casing is like a bent lip. I have repaired the rear casings many times as it saves the clients quite a few dollars. I have made myself a dolly/bucking bar that allows me to reform the corners as well as keeping the lip on the edge. You do not have to hit it hard at all as it is aluminium and quite soft.It is also necessary to reform the corners as much as you can as installing the screen is difficult, because the corners that are bent puts pressure on the glass giving you a greater chance of shattering the new screen or keeping the screen lifted away from the main body. I then use a needle file to make the corners smooth from any burrs that might be on there. At the moment I am looking for some liquid rubber to paint on the corners so that if people drop there iPads on the corners the rubber, when dry, takes some of the impact and protects the corner.
Hi Curtis Have a read of this post Will not power on, what could it be? This post I believe gives you good recommendations to start of. Also have a look at the logic board and see if you can notice any corrosion, if so do a isopropyl alcohol solution bath to help loosen the corrosion and using a soft bristle brush like a soft toothbrush lightly brush the corrosion off. The alcohol bath will also help remove any kind of moisture that may be on the logice board.