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livingonvideo13

macrumors regular
Original poster
Jun 19, 2009
243
0
I have replicated this problem a few times today. I am running my iPhone4 with Navigon using the GPS and plugged into the charger. It gets quite warm. I noticed if it gets to warm the brightness drops down quite a bit. 100% Brightness looks more like 20%. Going into the brightness setting will not bring it back up to full level but it will change the brightness. When I turn it off and wait about 30 seconds and let it cool down and turn it back on again, it goes to full brightness and it is fine until it heats up again. While driving it was ok in the car because of the AC but I left it on during Rest Stops and Lunch breaks and that is when it overheated and the brightness went down.

It maybe did this 3 times during a 7 hour drive.

Anybody else have their iPhone 4 do this?
 
Mine does that. It appears to be a means to cut down on the heat. If the heat increases or the phone stays on longer without cooling down, you get the temperature warning screen. It is a way to preserve the electronics in the event of excess heat build-up.
Apple lists the appropriate operating temperature for the device. I don't have the spec sheet handy, but you can easily find it.
And remember, the phone temperature is what matters most. If you have the phone in an air conditioned car where YOU feel quite comfortable, but in very hot direct sunlight, it's possible that the interior of the phone can exceed the operating temperature range.
 
For more information about this, take a look at the iPhone users guide. It's in Safari as part of your built in bookmarks (click and hold the bookmark icon). Look at "Support and More Information", then "iPhone Operating Temperature".
 
yeah, I got that too yesterday when using navigon. I had it propped up on my dash so I could see the map and didn't realize the sun glaring down on the metalic antena, absorbing all the warmth not to mention the heat being generated from the GPS and cellular radio.
 
This has happened to me too. Pretty much exact same thing. My 3GS never did it, but then again, it may not have been as hot when I was using it. I have no ac, so hopefully this new replacement unit will be a little better with heat management.
 
Ok thanks for the comments. I guess it is a pretty normal thing though and good that it does this instead of burning up the electronics. +1 for Apple!

I did have a case on mine and I am sure that can also trap the heat.
 
I had the same problem with a few navigation apps like Navigon, motion X, AT&T.

I actualy went to the Apple store. They couldn't figure out this problem they ran a test if it was ever overheated but it wasn't.

Than he told me the only thing he can do is exchange it for another one.
 
Well, as it turns out, my replacement unit has done the same thing. Although instead of just heating up to the point where it goes blank and gives the temp warning, it just dims the scene so far. It wasn't as hot as the day it did it the first time, but hot none the less. I also have a case on my phone, so I'll have to see if taking it off makes any kind of a difference. I wonder if the temp warning was just set to low, although the phone was very hot. My 3GS had gotton that hot before, but didn't seem to effect it.
 
Brand new iPhone 4, with screen dim, heat problems

Several days ago, I bought a spanking new iPhone 4, and also of not being a week old, it started to have screen dims as well. But I carry my phone around in my pants, and it's starts to create heat by the friction of walking around. I quickly realised, the friction and the heat where the problem of my screen dims.

I live in the Netherlands, and this is not a tropical country, so heat problems should not be a problem. I decided to go back to the store who sold me the iPhone 4 today, see if the can give me a replacement.
 
An old Casio digital watch does the same thing. They did it when new also. The solution is to stay out of the heat. No amount of replacements will fix it.

Or there is another solution. The new Super LCD, as well as the new Super AMOLED displays that Android phones use do not dim, until they are much hotter.
 
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