iPhone 4 turning itself off and wont turn back on!?

Replaced lcd/digitizer and one day later it started vibrating uncontrollably. Then it started showing the wrong time and charge percentage out of nowhere and upon taking it back apart and scrubbing, the problem was fixed.....for about 5 minutes. after behaving normally for a little bit, it just shut off while plugged in and i had to soft reset the phone (power and home button) to get it back. i have done this now 5 times and it never stays on. i also tried scrubbing again and the problem persists. I have never seen this before, please help!?!