Chosen Solution
I bought this phone off of eBay with a shattered screen. The top of the screen where the camera and speaker is was non existent (all the glass fell out). Got it in the mail and plugged it into my charger. Tried starting it up. White screen appeared with apple logo. Went away after a second and then went to black screen with battery symbol. Didn’t show lightening bolt. Sat around for a week until my new screen came. Put everything back together and made sure the ribbons were connected the correct way. Went to go plug it into my charger and same deal as before…black screen with battery symbol but no lightning bolt. Took phone back apart to double check everything. No change. I disconnected the connector to the battery and the iPhone will loop through with the apple logo. I even took the connector for the lighting socket off and reseated it…no change. Is this phone junk? What can I do to get it to turn back on? Should I try a new battery?
Since when you unplug the battery you get a boot-loop, my guess is the dock and charging circuit are OK, and you battery would be the first and most likely suspect in my opinion. Try a known good battery if you can get your hands on one. Otherwise order a good quality battery (iFixit’s batteries are my go-to; most others are junk, don’t cheap out) and test your phone with it.
