Power button worked for a bit after replacement, rear camera and flash

ok so i brought a iphone 5 and its said power button doesnt work, but i opened it moved the flex cable and everything i also unclipped the metal bracket and reattached it, then it worked for about 3 weeks perfectly but then it got harder and harder, for the phone to respond to the press so i would have to press it harder then it stoped working so dont know what to do about that.

The rear camera would work sometimes same with the flash, this was after the power button fix, so it would work on and off for about 2 weeks then it just stoped working altogether, front camera works well thanks.