Carefully inspect the box in which you sold your Nokia phone. It should be glued the sticker, which indicates the serial number of the phone and its IMEI code. Copy this 15 digit number. It should be noted that the first 6 digits designate the model code of the mobile device, in this case the first two indicate the country code of the manufacturer. The next 2 digits refer to the code of the final manufacturer, followed by 6 digits of the serial number and the last digit is a spare ID and often equal to zero.
Open the battery of the Nokia phone, gently pry and remove the device. Under it should be basic information about your phone: model name, serial number and IMEI code. The last must match exactly with the one you have copied from the packaging. This check must hold at the time of purchase of the device, to protect yourself from counterfeiting.
Turn on your Nokia phone, and type on the keyboard combination *#06#. This operation can be performed without inserted SIM card. In the result the screen will display the IMEI number of your device. If different from those indicated under the battery and on the box, it means that your phone Nokia pereproshivka.
In this case, you will not be able to serve in the service centers, and warranty certificate issued by the seller, you can just throw in the trash. Also if the IMEI number was not native to the phone, it can be a communication problem with the mobile operator. The fact that they activate the SIM card lock this value and already concerning it connects to the network. If the phone was pereproshit, it is likely that this IMEI number have a few devices that will interfere with the normal operation each other in the same network.