The thermal sensor check that causes the restart loop, which flex cable is responsible on your model, and how to read the panic log yourself.
So you just got your iPhone screen replaced and now the phone keeps restarting on its own every few minutes. Super frustrating, especially when it was working fine before you handed it over. Here is the good news. Your phone is not dead. This is a known issue and it has a specific cause.
Every iPhone has thermal sensors built into the flex cables inside the phone. Every three minutes the phone quietly checks in with all of those sensors to make sure nothing is overheating. If one of those sensors does not respond, the phone panics and restarts itself. That is why the timing is so consistent. It is not random, it is the phone doing a safety check and getting no answer back.
When a screen gets replaced, one of those flex cables can get nicked, torn, or not seated back in properly. The phone starts up, hits the three minute mark, checks its sensors, gets no response from the damaged flex, and reboots. Then it does it again. And again.
This is where it gets specific. The flex cable that causes the restart is different depending on which iPhone you have.
On iPhone 14 and iPhone 14 Plus the proximity sensor flex is almost always the culprit after a screen repair. That flex sits right in the screen assembly and is easy to damage if the repair is rushed.
On iPhone 14 Pro and iPhone 14 Pro Max it could be the proximity flex, the charging port flex, or the power button flex depending on what was touched during the repair.
On iPhone 15 and iPhone 15 Plus it is usually the proximity flex or the wireless charging flex on the back glass.
On iPhone 15 Pro and iPhone 15 Pro Max this one trips people up. The proximity flex does not cause restarts on these models. If your phone is restarting it is more likely the charging port flex or the wireless charging flex. A lot of shops replace the wrong part and wonder why the phone is still doing it.
On iPhone 16, iPhone 16 Plus, iPhone 16 Pro, and iPhone 16 Pro Max the same rule applies. Any flex cable that carries temperature sensor data can trigger the restart loop if it gets damaged or disconnected.
Your iPhone actually logs the reason every time it restarts. Go to Settings, then Privacy, then Analytics and Improvements, then Analytics Data. Scroll down until you see files that start with "panic-full" and open the newest one. Look for the words "SMC PANIC" and a code that starts with "0x". That code points directly to which sensor is not responding.
If that sounds like too much, just bring it in. We read panic logs all the time and can tell you in about two minutes what is going on.
Nine times out of ten it is a damaged flex cable that needs to be replaced. On iPhone 14 models that is usually the proximity flex. On 15 Pro and 16 models it might be the charging port or wireless charging flex.
One thing worth knowing is that cheap aftermarket screen assemblies often come with low quality proximity flex cables that fail even when they have not been physically damaged. If the shop that did your repair used a budget screen, the flex that came with it might be the problem even if it looks fine.
If a new flex does not fix it the issue is at the board level, meaning the connector on the logic board itself is damaged. That is a microsoldering job and a bigger repair.
iPhone 14, iPhone 14 Plus, iPhone 14 Pro, iPhone 14 Pro Max, iPhone 15, iPhone 15 Plus, iPhone 15 Pro, iPhone 15 Pro Max, iPhone 16, iPhone 16 Plus, iPhone 16 Pro, iPhone 16 Pro Max.
We see this every week. Someone gets their screen done somewhere else, the phone starts restarting, and they end up at our door. We will pull the panic log, find the exact cause, and fix it the same day in most cases. Check our iPhone repair page to see everything else we can take care of while we have it open.
If fixing it does not make financial sense on an older phone, we also buy iPhones for cash on the spot. Restarting, cracked, or completely dead, bring it in and we will take a look.
Walk in to 20503 Dequindre St Detroit, MI 48234. No appointment needed. Call or text (313) 900-1032.
Bring it in. We diagnose and fix the restart loop same day at 20503 Dequindre St, Detroit.
Or call (313) 900-1032