My son was given an lg k20 phone. I did a factory reset to remove all of the previous owner's personal information and now I get an unknown error when I try to set up the phone for him. WHat do I do?

SOURCE: reset lg vx5500 to original factory defaut?

ok go to your menu, then go to tools. near the bottom, it says phone settings. select that and then go to security. select that, and enter your lock code (if you havent changed it since you have had your phone, its the last 4 digits of your number), then select restore phone.

SOURCE: Reset Samsung A900 to Factory Settings

http://www.samsung.com/us/function/search/resultList.do?searchWord=A900

SOURCE: need to reset password for verifone omni 3740

If you press the F2 and F4 buttons and enter 1 Alpha Alpha 66831 and the terminal goes back to the idle screen then the system password has been changed or the battery is bad in the unit and will have to be replaced. Either way it will have to go to a repair facility to be corrected.

SOURCE: I need the factory master

other way is .......

*switch off your phone
*press *3&call button constantly.
*switch on your phone
*switch on it, your problem will be alright......

SOURCE: I have an old Nokia

For Security code forget reason You can reset it using the master reset code,For Factory restore you can go to store and flash it using the software,you can get the Master reset code at here
Unlock-free.com and reset from security lock...