6 
8 Can a screen problem trigger the random reboot?
i received a phone that won’t power up. my first though is usually drained battery and potentially bad charging port board. so i opened it up to pop in a fully charged battery. right away noticed that the LCI was red, but that doesn’t automatically mean the phone is dead.
with a charged battery the phone booted up just fine and everything seemed to work except a deadspace on the digitizer right around the area where you enter your email address on the Apple ID screen. there simply was no touch recognition in that band (if you split the screen into 5 bands, top to bottom, this would be the second from the top).
while i was further troubleshooting that, the phone rebooted, but would boot normally to the home screen. then 4 to 6 minutes later would reboot again, and again. etc.
figuring maybe the water damage i soaked the mobo in 99% IPA, gently scrubbed what i could with a soft toothbrush , then let it dry in my server closet for a couple of days. only wish i had an ultrasonic cleaner, but i don’t. i also cleaned as much of the case and components with IPA and q-tips.
upon reassembly still had the same issue.
i next tried the problematic board on a good phone, and a good screen on the problematic phone. to my surprise, the reboot travelled with the screen and did not appear to be the wet motherboard (phew).
so my question is, is this just a fluke or have any of you seen this situation where a (water) damaged or malfunctioning display can cause a phone to repeatedly reboot on its own? and if so, can anyone shed some light on to the underlying details behind this?
i just never figured a display could be the cause of a random reboot.
Cheers
Esta é uma boa pergunta?
Does this also happen with the top flex disconnected?
por Chris Stables
you mean the selfie cam and ear piece?
haven't tried that. will do so and post reply
por B C
Yes. That one.
por Chris Stables
i did that. and it looks like it did the trick. so definitely swap out the selfie cam. would not have thought to look at that component.
but this brings us to issue #2, if you refer back to the original post, i added a picture of the white dead-band, illustrated with a finger-painting app.
is this fixable? or should i just chuck the screen and get a new one (with a new camera)? i have a feeling the latter would be cheaper.
thoughts?
and thanks for the first tip
por B C
@imicrosoldering
additional information.
the phone screen (without the selfie-cam connected) ran without reboot for 12 hours.
for sanity check, i reconnected the cam for a test, then i was going to try again with a different cam actually connected (and the screen with the 2 flex only).
but what happened is that with the original cam reconnected, there was no reboot in almost an hour (i'll let it run longer for more observation).
the only thing to note is during the time of this testing, the phone was sitting open (the screen was not sealed to the case) in my server closet which is roughly 15 degrees warmer than the rest of the house.
it's possible the extra time in the warmer room may have dried out any residual moisture in the camera.
i don't know enough about iphone component electronics to even know if this would be a factor or not, but it's hard to argue with the fact that the screen no longer (at least in this initial testing) seems to reboot.
will post an update in a couple of days.
por B C