The Nokia 6233 is a remarkable mobile phone, with high quality stereo speakers and 3G compatibility, it is still a great phone to use today. If you have network branding logos on the housing and on the menus, it is very likely it is locked onto that specific network provider. This means that you cant use a different network provider sim card in your phone, since it will be restricted from any use. To overcome this problem, you would need to unlock the phones firmware to all networks. Since the Nokia 6233 is a old mobile phone, there are many free unlocking calculator generators online that you can use for free. All you need to do is generate the unlock code, type it and your all done. There no need for special unlocking software or cables.
1) Remove the back battery cover and remove the inserted battery. Then open the sim card hatch to remove the current sim card. Reinsert the battery pack and replace the battery cover.
2) Hold down the power button found at the top of phone to switch it on. Enter the following code into the keypad: *#06#. The phones IMEI number will now be displayed on screen. Make a note of this number on a notepad.
3) Go find an available online unlocking generator tool. Select the model which is 6233 and the network provider it is locked on. Then enter your IMEI number into the appropriate box and click the Generate button. There will be many unlocking codes displayed on screen for you to try out.
4) You will notice that all of the unlocking codes will start with #PW+. To bring up the PW+ characters onscreen on your phone, you will need to press the star button a few times to select them. So start of by entering the first unlocking code from the list and keep trying them after one another until one finally works. If your Nokia 6233 is successfully unlocked a message will appear saying Sim Restriction Off.