How to Enter Unlock Codes on Treo 600, 650 and 680 Cell Phones:
-Remove Treo battery,
-Insert incorrect SIM card (Any simcard that the phone does not accept)
-Power on Treo, ‘Sim not allowed’ is displayed, click OK
-Go to the dial pad, and use the stylus to enter MEP code . You must enter the code in the following fashion:
*#*#(MEP-CODE)# then press dial (Where (MEP-CODE) is to be replaced by the ACTUAL code supplied by the unlocking software).
For example if the software supplied 12345678 as your MEP code for your phone , you must enter the code as follows:
*#*#12345678# , then press dial
Again the above numeric code is for illustration purposes, please enter the MEP code as supplied by us. Phone will reset and display sim lock removed
Error Message: “The SIM Lock has NOT been removed from this phone”
Solution 1: Please make sure you are entering the correct code and enter it using this method *#*#CODE# dial
Solution 2: If the phone says that the SIM lock has not been removed, ensure that the phone radio (wireless mode) is on.