BenQ S660C - Manual (Page 165)

Menus 151
Phone Lock
Activates/deactivates or changes the phone's startup
password. The startup password prevents unauthorized
persons from using your phone. Once the phone's password is
activated, the phone will be locked down when it is turned on
unless this password is correctly entered. If an incorrect
password is entered, your phone will remain locked down,
and cannot be unlocked even if the SIM card is replaced by
another one. When the phone is locked, you will only be able
to make emergency calls.
Once the phone password is activated, you must enter the
password each time the phone is turned on in order to unlock
the phone (there is no limit on the number of attempts to
enter the phone password).
The procedure for setting the phone password is the same as
for the PIN1 code (the default phone password is 1234).
SIM Lock
Using this feature, you can prevent unauthorized persons
from using your phone with other SIM cards. After you
activate the SIM Lock feature, only the SIM card present
when the feature was activated will be accepted by the phone.
If a new SIM card is inserted in the phone, when the phone is
turned on and a PIN code is entered, the phone will request
entry of a SIM Lock password (there is no limit on the
number of attempts to enter the SIM Lock password.
If the password is entered correctly, the phone will be able to
recognize the new SIM card and use it normally. The next
time the phone is turned on with this SIM card inserted, the
phone will not ask again for you to enter the SIM Lock