Chosen Solution
After battery replacement it won’t turn on anymore. No reaction on the screen, no haptic feedback - no vibration, phone offline in “find my device” What I tried: plug in to chargerlong press power onlong press power on + volume downeven tried to reconnect the old swollen battery which worked before, but with the old battery which worked an hour ago it’s also dead.I fully reassembled the device in case it does some integrity checks before booting, (Fingerprint sensor, etc.) Any ideas what I can try? I did not notice any breakage during replacement, nothing had to be forced. I have no idea what to try.
Actually… … pressing down volume and power real long did vibrate. So it turned out the screen was not working. What worked for me was to check the mainboard connector right to the battery, it was a little lose - probably came undone when I wedged the battery out. hope this helps someone
