iPhone 7 wont boot after case opened

Hi all

I’ve just gone to replace a battery in an iPhone 7 and had to abort after I realised I didn’t have the tri head screwdriver that the 6S didn’t use. Anyway, I put the phone back together with the intention of going back to it.

Tested it to make sure it was still working ok, and it was stuck on the black screen with white Apple logo and stuck in a loop. Plugged it into a laptop in recovery mode, successfully “updated” the phone without restoring it, unplugged it and was still the same. Took it back apart and held down the front camera ribbon and it booted to a different screen - plain white with “Press home to restore”. But Home button doesn’t appear to be responding. It’s my friends phone and he doesn’t want to lose the data on it so I’ve been reluctant to do a full restore yet. Just wondered if anybody had any suggestions before we have to take it to a shop.

Have done plenty of iPhone 6S’s previously to this so it’s completely stumped me as to why this has happened.