Answer to: Won't power on, vibrates every 5 seconds, with replacement battery.I got it working!!! I had the same vibration every 5 seconds & black screen after replacing a cracked display & plugging in my i-phone 5. I was so frustrated & spent over an hour re-seating all the ribbon cables several times over & everything looked good. Finally I took the advice of someone on one of these forums --- held down the lower round button & the top on/off button at the same time, for 15 seconds until the white apple showed up on screen. I let go & it came alive!!! I was so thankful my prayer was answered.