I found this guide to how to reset nokia security code to default hope this will be help you tipsandguides.blogspot.com
How To Reset Master Security Code For Nokia 3220?
Forget security phone codes
Master security code for nokia 2760
Just throw your old one and buy a new one year
Phone start-up failed. Contact the retailer
There are different master code for nokia models and it also vary from manufacturing location. If you want to unlock your nokia mobile then here you will get free nokia unlock codes for nokia mobile.
Below are some reset codes for various Series 40, 60 and the new Series 80 Communicator series (Nokia 9300/9500):
Full Reset: (clears everything off the phone memory!! Be sure to back up your contacts!!): *#7370#, 12345 and then Yes.
Soft Reset: *#7780#, 12345 and then Yes. (Also works on Nokia S40 phones as a full reset)
*#335738#
*#delset#
This deletes the Email, GPRS, MMS settings that cannot be erased via phone options. (Newer Series 40 phones only i.e. 6230(b))
Nokia 9300 (not confirmed) and Nokia 9500:
1. Turn off phone and take out battery
2. Insert battery, and while it boots up press and hold Ctrl + Shift + F
3. After a few seconds you will be asked if you want to format or cancel
Below are some reset codes for various Series 40, 60 and the new Series 80 Communicator series (Nokia 9300/9500):
Full Reset: (clears everything off the phone memory!! Be sure to back up your contacts!!): *#7370#, 12345 and then Yes.
Soft Reset: *#7780#, 12345 and then Yes. (Also works on Nokia S40 phones as a full reset)
*#335738#
*#delset#
This deletes the Email, GPRS, MMS settings that cannot be erased via phone options. (Newer Series 40 phones only i.e. 6230(b))
Nokia 9300 (not confirmed) and Nokia 9500:
1. Turn off phone and take out battery
2. Insert battery, and while it boots up press and hold Ctrl + Shift + F
3. After a few seconds you will be asked if you want to format or cancel
Go to menu select packet data. It will reset.