12-14-2016 11:44 AM
Some of you are aware of the Field Test Mode on your iPhone. Entering that mode will display the signal strength in dB instead of those vague "bars". Problem was that it would revert back to the bars if you did anything else.
So for all you people who would prefer an actual signal strength displayed all the time, follow this procedure:
1. Dial *3001#12345#* just like before. The Field Test Mode should open and you should see dB's displayed instead of bars.
Now here's the hack!
2. Hold the Power button down until the "slide to power down" prompt comes up.
3. Hold the Home button down and while doing so, start mashing the volume up and down buttons quickly.
4. If you do the mashing correctly, your phone should return to the field test mode and the signal strength is now in dB's.
5. It will continue to display in dB's unless you touch the very top left-hand corner of the display. You should be able to toggle between bars and the dB reading.
06-16-2017 9:33 AM
@Nat0515 - thanks for posting. I didn't think there were any issues so it's nice to have confirmation.
06-16-2017 10:42 AM
@kurgan0789 - I don't know for sure if the iPhone 7+ has been tested. If it truly doesn't work on the iPhone 7+ then it's probably due to a hardware change, in which case there is nothing the AT&T can do so you'd need to take it up with Apple, unless someone figures it out.
06-16-2017 11:04 AM
As far as hardware differences, the iPhone 6 and 6+ are running a dual-core, 64 bit A8 processor. The 6s, 6s+ and SE are running the dual-core 64 bit A9 processor.
The iPhone 7 and 7+ are running the A10 Fusion processor, which is a hybrid quad-core, 64 bit processor with 2 high-performance cores that run up to 2 times faster than the iPhone 6 and 2 high-efficiency cores that can run at just 1/5 the power of the high-performance cores.
Perhaps this difference in processors could be the reason why the Field Test Mode doesn't run on the iPhone 7+, but I really don't know. If they are all running iOS 10.3.2, then one would think you could rule out the OS as the cause but again, I don't know.
Or kurgan0789 is not entering the volume key portion of the hack correctly......?
12-01-2017 3:52 PM
The Field Test Mode dB doesn't appear to work when using an iPhone X. Other information is available after dialing the Field Test Mode number but the signal strength in dB is not shown in place of the bars. Bummer....
12-01-2017 5:16 PM
01-20-2018 7:56 PM
I cannot get dbs via the speed test at all.at all. Only bars. Have done it in the past. What am I missing? Tried hack to no avail.
01-20-2018 9:26 PM