Peek at the hidden secrets inside your iPhone's brain and find out what's really behind those mysterious signal dots with this quick, free little trick.


There’s nothing more frustrating as an iPhone user than watching that tiny last signal dot in the top left hand corner disappear. But with this clever little trick, you can into delve into your iPhone’s secret settings to find one last precious morsel of signal to cling onto.

The trick is simple. All you have to do is open your iPhone’s keypad, dial the short code *3001#12345#*, and hit the call button. Just like this:

iPhone Field Mode

This nifty little shortcut will take you briefly onto a grey screen, and then into what’s called your iPhone’s Field mode, which basically gives you access to all of the secret settings and diagnostics you’ve always been dying to hanker at.

Here’s the coolest thing, though. As soon as you’re in Field mode, you’ll notice that those pesky signal dots have been replaced by something else, à la this screenshot:

iPhone Field Mode 2

That bizarre little -90 Proximus message in the top left corner? That’s your iPhone’s signal strength in exact decibels, rather than bar format, and it’s a much better indicator of how much signal your phone’s actually got.

For reference, anything about -80 is about the same as full bars. The best signal you’ll ever get is probably going to be around -40. Below -110 is the equivalent of zero bars, meaning you’ll probably find it difficult to make a call.

If you’re a fan of your new little signal indicator, you can choose to keep it by pressing and holding down the power button. When the message to turn off the phone pops up, just press the home button. If you prefer the standard dots, you can just quit Field mode by hitting the home button.

After more cool iPhone hacks? How about turbo-charging its audio and battery life with this neat Arcam gadget.