The iPhone can do more than you think. With special codes you can unlock helpful functions in the iPhone.
The iPhone can do more than meets the eye – without any hacks or apps. Various key combinations hide secret menus and displays that are actually only intended for technicians. TECHBOOK reveals the secret codes for special functions.
Leave voicemail without calling
There are those moments when you call someone and you really don’t want him or her to answer. But there is a way to speak directly to the other person’s mailbox. Each provider has a specific code for this: Vodafone 50, T-Mobile 13 and O2 33. If you want to send a message to a friend’s O2 number, you first dial the area code, then the corresponding code and then the rest of the number, for example 0176-33-xxxxxxx. Then the mailbox goes straight away and you can leave a message.
This is how you test the reception strength exactly
The “Field Test Mode” function is also hidden in the iPhone. This provides details about the connection quality and WLAN encryption modes. The reception is given exactly in decibels and you can see which radio masts the smartphone is communicating with. To open the mode, simply dial *3001#12345#* on the phone and call. The scale for reception is given at the top left and usually starts at -40. Anything from -110 is rather bad reception, at -120 the call will probably falter or break off.
You can also activate the exact reception strength permanently. To do this, open the Field Test Mode, then hold down the power button for a long time until the “Switch off” button appears. Then press the home button until you get back to the home screen.
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Activate call waiting/toggle
With the *43# you activate on the iPhone the “Call Waiting/Call Swap” function. If you do that, you’ll get an alert tone when someone else calls you while you’re on a call. You can then accept the other call or switch between the two calls or start a telephone conference using the corresponding button. To deactivate the function again, type in #43#.
Call anonymously
Would you like to quickly hide your number for outgoing calls? There are two helpful codes for this. with * # 31 # go out all the following calls with a suppressed number. Until you enter the same code again to disable the feature again. with #31#telephone number you switch the following call to the respective number to anonymous.