Traditionally, To turn iPhone completely off,
you need to press and hold the Sleep/Wake button for a few seconds until the red “slide to power off” slider appears, then slide the slider. Now you need to start your iphone again.
But now, Press and hold the Home button and the Sleep button to restart your iPhone. A white light will flash, the screen will shut off and then turn back on! That easy!
Keep holding until the screen turns back on.
Note: When iPhone is off, incoming calls go straight to voicemail.
On the main screen type *#92702689# (*#WAR0ANTY#)
It will take you to a secret menu where you may find some of the
1. Displays Serial Number.
2. Displays the Month and Year of Manufacture
3. Displays (if there) the date when the phone was purchased (MMYY)
4. Displays the date of the last repair – if found (0000)
5. Shows life timer of phone (time spent on calling/receiving phone calls)
To check the phones Software version for Nokia Mobile.
On the main screen type *#0000#
If the above code does not work
then try *#9999#
1st Line : Software Version,
2nd Line: Software Release Date,
3rd Line: Compression Type
Only for Nokia Cell phones
Dial *#4720# to activate Half Rate Codec – Your phone uses a lower quality sound but you should gain approx 30% more battery life.
Dial *#4720# again to Deactivate Half Rate