Chosen Solution
I replaced the battery in an iPhone 6s for someone and now after replacement the battery is stuck in boot loop. I followed guides how to do the whole thing, was very careful going through. Checked all my connections and when I powered it on after I installed the new battery, it’s stuck in a boot loop that never ends. Plugged in or not it stills is stuck. It won’t recognize in iTunes either so I can’t even restore it.
Was the old battery working at all? If it still works try putting the old one back in and see if it still boot loops. Could be just a faulty replacement battery.
