Field Test Mode Hack IMPROVED!!!!
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.
I am not an AT&T employee.