I colleted Following information from webs , I have not tryed these... , but I think it will be usefull...
Unlocking NEC C313 & C616, E808 etc100% work
1st Method:
1)Insert any 2G simcard when mobile set is off and then turn-on the phone
2) #4960*xxxxxxxx# Send
3)*4960*xxxxxxxx*xxxxxxxx# Send
4) Turn-off the phone and turn-on again!
Remember 5 points,
1) Note: "xxxxxxxx" is any number (8 digits code).
2) This unlock method ONLY works with one type of (2G)simcard. If you change another (2G)simcard, you have to unlock again!
3) If you use again the 3G sim card, you have to input only the (8 Digit) xxxxxxxx code.
4) The unlock code is depended on the phone firmware version. There are 2 version of unlocking methods.
For some version, don't press "send" but just the code all the way.
5) I think that the NEC *** mobile set which has SP Lock On will not be unlocked.
2nd Method:
Just put any other simcard and press cancel then enter any 8 digits(may be 00000000,12345678 etc).Phone will say usim lock is off.
To change into 2 gsm mode ,dial 112 from phone so it says" changing from 3g to 2g/gprs mode"
then after few seconds press cancel button and phone will remain in 2g mode and display 2.5 icon on phone.
(its only temporary but works ok)
3rd Mehtod:
i think it opens with #7320*xxxxxxxx# but xxxxxxxx=?
4th Method:
Power off phone and insert a 2G sim
Power on phone
It will say insert USIM OR USIM error- just press the emergency button
don't enter anything just wait about 3 seconds and it will ask for unlock code
enter 12345678 then press ok
dial 112 (emergency number) it will ask to swap networks (Exchange Networks) say YES
as soon as it swaps, hangup otherwise you'll be onto emergency services
wait about 15 seconds and your phone is partially unlocked
5th Method
1)577349765++ hold 2 (for 5 secs) and 393++
phone will switch off and back on/ phone is unlocked
SP-Lock (of Mobile set): The 'SP-Lock' (Service Provider Lock) prevents you from using your handset with a different service
provider other than the one you (currently using or unlcok for) originally purchased it for.
SIM Card Lock (of Mobile set): The 'SIM Card Lock' prevents you from using your handset with a different SIM Card other than
the one you originally purchased.
CODES TO CHECK:
SP Lock Info: *#3210#
SP Lock Remover: ##3210#
Network Lock Info: *#7320#
Network Remover: ##7320#
Corporate Lock Info: *#8140#
IMEI & Sofware Version: *#06#
Firmware: *#2820#
these are the codes which unlocked phone
The code is entirely IMEI based and is of the format #7320*xxxxxx#
spck #3210*80277733#
nck #7320*62619113#
cp #8140*69100543#
sim #4960*20004175#
remember to take your usim out of the phone and switch it back on and when it says emergency number only then enter
the codes.if they are successful you will get the messages network lock off and sim lock off.good luck.