Why is my new iPhone 16 not turning on?

Why is that, Lawrence? I thought it was a good idea to turn it fully off at least once a day. Overnight seems like a good time. I keep it near my bed but turned off because I don't want it to ring or vibrate if someone calls in the middle of the night. In an emergency, I'd be reached on my landline. But I also want the mobile handy if I need it for some reason.

I have been turning my iPhones off nightly ever since my iPhone4S because Do Not Disturb doesn't block all the missing person alerts that go off here at least weekly in the middle of the night. They come blasting through anyway. The automatic backups happen at other times anyway.

I'd like to thank everyone for all the helpful hints and ideas. I can say that, once I succeeded in restarting the iPhone 16 Pro Max and installing the patch that was waiting, I have not had a single repeat.

My intuition is that there is a timing issue buried in the microcode on the chip that is compensated for by that last patch. Who knows? It might have been a bit hit by a random cosmic ray. I just recall that in my circuit design class (decades ago!) it was devilishly hard to guarantee a clean boot from a powered off state especially when there are billions of circuits on the chip. Propagation delay across the chip can be an issue that is hard to predict. I'll be happy if the repeat rate is below a few times/year.

The issue occurred the first night after purchase. There were a bunch of patches that loaded in quick succession after I got the phone home. There was one more that installed in the morning after I use the emergency startup sequence described above. I don't have a list of installed patches or that the patch actually helped with this issue. It may have been a coincidence. Either way, the issue has not reoccurred. At least now I know how to do a forced startup. The timing of the quick press sequence seems a bit sensitive though. It took me several tries before it worked. Pressing the volume buttons in the right sequence also seems important. Lawrence's advice is accurate. Slow deliberate pressing isn't fast enough, but "Flight of the Bumblebee" is too fast.

Whatever it's called, how do I get what Science Curmudgeon is talking about that fixes the problem?

I should note that I got my iPhone 16 pro directly from Apple less than two weeks ago, as a replacement under AppleCare for the same that I received and broke a few days before.

Randysea wrote:

Whatever it's called, how do I get what Science Curmudgeon is talking about that fixes the problem?

I should note that I got my iPhone 16 pro directly from Apple less than two weeks ago, as a replacement under AppleCare for the same that I received and broke a few days before.

Did you follow the instructions in the Top Ranking Reply near the top of this page?

I did follow your instructions and upvoted them, too. It works but isn't a permanent fix to an ongoing problem.

When I got my replacement 16 Pro, I let it immediately update to 18.2. I've had two "not turning on" events since then. The second was this morning. Most of the time (in two weeks) it's started normally.

hmmm... I got two updates a few hours apart the same day I got the phone (The first in the store and the second after I got home). After the forced startup the next day, I got one more. (I used the phrase "a bunch" to indicate "several".) I have both "beta updates" and automatic updates enabled. My iPhone now claims to be running 18.1 and is "fully up to date". I have not received the 18.1.1 or 18.2 update yet. Is there a way to expose the version history of the phone?

I suspect that Apple's update process knows the exact configuration of the chipset inside my phone and flows a correct update accordingly. Not all phones are from the same production lot. There may be relevant variations that the update process needs to consider. I also do not know the timing algorithm for updates.

Updating a billion phones across the planet is a complex task and there is more than one way to do it, e.g., the DevOps daily method of near continuous micro updates WebEx uses is the other extreme.

As soon as I turned off the beta release feature, 18.2 became available! I had always assumed that the beta release would be ahead of the latest non-beta release. That hurt my head a bit. I've always liked getting an early look at new features.

It nothing else works, take the iPhone 16 to an Apple store and use the warranty to replace it. There might be a manufacturing defect on one of the production lines at one of the factories that wasn't caught before phones were shipped to stores. Quality Assurance is a self-correcting filter, but there are occasional escapes. That's when manufacturer warranties help.

Your reply to elainefromocola was not really on point. You wrote:

Apple is doing nothing for the problem with your phone

unless you contact their support. This is a problem specifically for

your phone and perhaps a few others, but does not happen with around 100 million other phones.

The comparison is not to 100 million phones. It is to how many users of THIS SITE have iPhones 16s and have even thought they might find help here. So far, 130 of them have said they have the same problem. The number seems to be going up every day.

I am one of those people, as you can see by my earlier posts. I have no speedup, etc., apps installed. I also doubt they could cause this particular problem.

I will say that your comment about contacting Apple directly and describing how to do it seems helpful in theory. However, it would be even more helpful if anyone reported trying this and actually getting the problem fixed. I haven't had the problem in a week. If I do again, I will follow your approach. So thank you for that.

I had the issue of “my iPhone 16 won’t power on”. I came across this discussion via bing on my XBOX series X. Your instructions are precise and correct. My iPhone 16 booted up on the first attempt following your directions. Thank you Mr Finch.

Since I updated to iOS 18.2.1, the problem has not recurred. I have tried leaving my 16 plugged into the charger all night but turned off, fully charged but not plugged in, etc. Nothing triggers the problem.

Coincidence, sunspots, or ?? Anyway, I'm glad not to have any problem with my iPhone not turning on. Fingers slightly crossed, of course.

Thank you for this tip. it worked and my brand new phone turned back on. Does any one know why it wouldnt power back on normally? am i going to have to do this every time i shut it off? should i shut it off? etc

Is it possible that not pressing the power button long enough on startup can cause the phone to go into the failed startup state and then need the forced restart procedure? I was able to reproduce the effect a few days ago. Can anyone confirm this is the case generally?