Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

Master

Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

Now you can put your iPhone into field test mode, which will allow to easily and precisely test your cell signal reception quality. You just need to follow these two easy steps:

 

• First, upgrade your iPhone 4—or any iPhone—to iOS 4.1.
• Dial *3001#12345#* into your phone.

 

Done. The signal bars will be replaced with a number (like -85). The more negative the number, the worse the signal is.

 

Example: -110 is worse than -85. Once activated, you can switch between signal bars and number by touching on the number.

 

Try the test mode now. Then use a finger to connect the two metal bands on the lower left corner, over the black plastic strip. That will short-circuit the magical gap and bring the phone's signal down quite significantly.

To get out of the field test mode, just hit the home button. [Thanks KTK1990!]

 

Story link found  here.

Message 1 of 27 (11,511 Views)
ACE - Professor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

 


GeekBoy wrote:

How about immersing the bottom half in a glass of water and tring it for us?  Smiley Very Happy


Yeah. You gonna buy the replacement phone?

 

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 16 of 27 (9,897 Views)
Mentor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:


UNSC_REACH wrote:

I just want to put this out there: Once you "force quit" the field test, the bars/db option will only be removable with a non-backup restore.


I've restored then restored from backup many times and it didnt work. Also, when I had a 3GS, I bought a iPhone 4 - I did a backup restore and the db's came on my new iPhone 4, it was running iOS 4.0. So the backup carries the db option. So once you back your phone up with the db's, you cannot go back whithout using older backup, or just starting from scratch.


Not that I care, personally I love the db's, just wanted to make everyone aware.


Interesting, so I assume when 4.2 is pushed that will bring back the bars only? Otherwise you have to restore from a previous backup and lose pictures etc?

Message 17 of 27 (9,853 Views)
Mentor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

i know this may be out there as far as this goes but i had 3 days left in my warranty for my 3gs and went to apple with a battery issue. they said that the phone is in warranty but due to the fact that the bars were gone and the signal strength is showing i did some sort of jail break on my phone and would not deal with the phone since it was jail broken. i tried to explain to them that it has never been jail broken and that i can easily put the bars on there. it is just showing the signal strength. well that was no good. they were sticking that it was hacked somehow and voided the warranty. so just incase anyone plans to take phone in to apple for any reason make sure that you have bars showing.

Message 18 of 27 (9,825 Views)
Professor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

MC_Hammer, I've had the db's for a while now, several updates. I've even updated to 4.2 beta, same. I dont think there is any way to get rid of them otherwise.

Message 19 of 27 (9,803 Views)
Professor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

[ Edited ]

user3977, great point! I've been to Apple more then once, with the db's showing but forgot about it and they didnt notice. But I can easily see how inexperienced genius bar agents could think that. Kudos for bringing that up!

Message 20 of 27 (9,802 Views)
Highlighted
Professor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

That's correct it's saved in the backups. I had the db's on my iPhone 3G for two years and when I got my iPhone 4 I used my backup files to set it up and still kept the db's. Apple removed the option in iOS4 and you couldn't get in field test mode on a iPhone running 4.0, when I had a problem with my iP4 and set it up as new I lost the db's and couldn't add them back until 4.1 came out when the field test option returned. As far as Applecare it is not a Jailbrake and doesn't modify Apple's OS, both my Apple Store and local AT&T store were the ones who showed me how to do it. I also had my iP4 replaced at a Apple store with the db's on it (was replaced due to shutting down by itself 4-5 times a week)..

Message 21 of 27 (9,863 Views)
Mentor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

I'd rather have the bars most of the time, so I did a full reset. Took a few minutes to put everything back, but it wasn't a big deal.

Message 22 of 27 (9,833 Views)

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

Or you could just touch the numbers and the bars will show.  Just leave it that way.

Message 23 of 27 (9,761 Views)
Mentor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:


millertimer wrote:

Or you could just touch the numbers and the bars will show.  Just leave it that way.


Mine kept reverting back to field test mode and I got tired of it.

Message 24 of 27 (9,708 Views)
Master

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

 


MC_Hammer wrote:

millertimer wrote:

Or you could just touch the numbers and the bars will show.  Just leave it that way.


Mine kept reverting back to field test mode and I got tired of it.


Not sure why it kept doing this for you. It worked for me immediately after holding the power key for 5 seconds, then pressing the home key. I am now able to go back and forth between the bars and the number reading without a problem.

 

Message 25 of 27 (9,663 Views)
Master

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

 


MC_Hammer wrote:

I'd rather have the bars most of the time, so I did a full reset. Took a few minutes to put everything back, but it wasn't a big deal.


I'm the exact opposite, as I feel that the best and most reliable way to measure the reception on any phone is with the numbers, therefore I have my iPhone set to the numbers most of the time.

 

Message 26 of 27 (9,657 Views)
Mentor

Re: Check Your iPhone 4's Antenna Reception With Field Test Mode In iOS 4.1:

[ Edited ]

Irish Rose wrote:

 


MC_Hammer wrote:

I'd rather have the bars most of the time, so I did a full reset. Took a few minutes to put everything back, but it wasn't a big deal.


I'm the exact opposite, as I feel that the best and most reliable way to measure the reception on any phone is with the numbers, therefore I have my iPhone set to the numbers most of the time.

 


I agree 100%, for some reason it was bugging me and it kept reverting back to the db on its own, so that's why I did a reset.

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