On many devices such as the Nokia 660 the ability to "soft reset" your device is as easy as typing *#7780# then phone will then tell you that your Symbian device is resetting and that all apps will be reset to their initial factory install. Before the process can complete however you'll need to enter your security code, the default for this code is 12345, if that doesn't work try 000000.
In this particular case your device is simply rolling back your devices networking and file capabilities just as you would do on a Microsoft Windows install. Once you're phone resets you still have all of your applications installed as a "Soft Reset" only restaurs factory default device settings, it doesn't mess with your applications or other file information.
Hard Reset – Code Method
The Hard Reset code method to format Symbian s60 is just as easy as the Soft Reset method with a different code. Simply type *#7370# and you'll be asked once again to enter your security code, type 12345 or 00000 if the first code doesn't work. You're phone will then restart.
With the hard reset method your default factory applications will remain on the device, however any third party applications you have installed will be completely deleted after the device resets itself.
Important Information: Make sure your battery is fully charged, or that your device is plugged into a power source. If you lose power during the hard reset it can cause serious damage to your device, possibly making it unusable, and forcing you to send it back to the manufacturer to be repair. Just avoid the repair costs and make sure your device doesn't turn off before its suppose to when using this method.
Flashing Your Symbian S60 Device
I don't recommend this step unless your receiving a blank screen, your device continues to freeze up or act out of the normal after the above steps are taken, or you have unexplained device hiccups that can't be solved with conventional methods.
Here's a quick step by step flashing guide for Symbian S60 based devices.
1. Fully charge your devices battery
2. Backup all of your contacts and other files onto your computer or a memory card of some type.
3. Turn off your device
4. Press the Green Dial Key, Star Key, and Three key. Hold those keys down while pressing the power button.
5. Continue to hold down those keys until you see the "Phone is Formatting Screen" of even just the words "Formatting" or something of that nature.
The device is now formatting, make sure you don't turn it off or press any buttons or any other options during this time. Once the device has flashed it will be reset to the exact factory default settings found right out of the box.
The Symbian S60 soft and hard system reset steps are easy to follow and can provide quick fixes for many device issues. I would suggest starting with the soft reset, moving onto a hard reset and if all else fails trying the device flashing method since that particular order will assure you take the least amount of risk to begin with.
Before trying to format Sybmian S60…
Always remember before resetting your device to back up all of your device information including phone numbers, contacts, apps and any other important files.