Iphone Boot loop

[pgodfrey1992]

I work at a device repair shop.

As of the last couple of weeks, I (being the Technician) have been experiencing problems with Iphones coming into the store, Functioning normally after the repair has been completed and the customer coming back in a few days later with Boot loop problems. Two devices have came in over the weekend, 6/5/17, an iphone 6 and an iphone 7.

For the Iphone 6:

The repair was a battery replacement.

*I tested before repair functionality, camera, microphone, charge port, siri, cell network, wifi, LCD, Digitizer, Touch ID, 3D touch, speaker all functioning normaly

*replaced battery (I know the older models boot loop issue or battery percent issues usually is a result of pry damage. Iphone 6 does not have the transistors and resistors are located next to the battery connect)

*Powered on device and tested the functionality again Everything worked

When the Device came back in-

*Device was in boot loop, I asked customer if it got wet, dropped, opened and when the problem arose. customer stated neither occured, nor was there signs of this.

*replaced with new battery- same issue
*replaced with another new battery- same issue
*removed battery and plugged in device through ac- same issue
*replaced with old battery- same issue
*removed Prox sensor assy cable and powered on- same issue
*removed touch ID, home button cable and powered on- same issue
*replaced with new screen- same issue

Connection to Itunes

*I always start by having Itunes attempt to software update the device
*Itunes downloads update, extracts, and then disconnects phone to continue with update.
*Phone restarts out of recovery mode
*boot loops for 2 or 3 intervials
*computer idicates with audible sound of disconect, reconnect, and
disconect (I use a windows)
*Phone boots finally into recovery mode by then Itunes hits back with
Generic Itunes harware issue code 4013
*Attempted to restore phone in recovery mode, same issues as noted above
*Attempted to restore phone in DFU mode, same issues

Now my question is has anyone experienced this problem before? If so were you able to recover/restore phone?

I assume the device was up to date with it being ios 10.2, never repaired before, and never jailbroken.

Now the Iphone 7 was a screen replacement, ( I am unaware if this model has the same logic board damage with the screws incorrectly place, but they are three small and one larger one with the one larger screw to the rightmost hole.)

*Note---Never had a boot loop issue yet with Iphone 7 repair, most common issue in shop is the Touch ID getting damaged and is not repairable without Microsolder or an apple appointment in a store.

*To try to repair this issue-

*new battery- same issue
*old screen- same issue
*new screen- same issue
*removed prox assy- same issue
*removed touch ID/home- same issue
*soft reset/ hard reset-same issue

*Restore and software update in itunes failed Error 4013, DFU mode failed
*Checked Itunes for update
*reinstalled Itunes
*checked cables
*changed USB ports

Itunes failed to recover or restore iphone

 

[Just_Me_D]

All you did was change the battery initially, correct? If it functioned properly when you gave it to the owner then I tend to believe the owner caused the issue either by attempting to do something or unknowingly, but that's just a guess on my part. I can't think of anything that would cause the problem based on the work you performed. Anyway, hopefully others will offer their opinions and/or recommendations soon.