Samsung SGH-G600 IMEI reset to all zeros after using so-called unlock code

Call the service provider and get the master reset code and reset it from security lock.

Hey,
Call your service provider to ask your Samsung Network Unlock Code. when you change your current network provider you must need to Unlock your Samsung first. after unlocking you can use your Samsung to any network.but network provider take time to give your imei unlock code.
second option is,
you can buy your Samsung Imei Unlock Code from third party . this is safe way to Unlock your Samsung . they will charge little amount but they give your Samsung SGH-G600 Imei unlock code immediately.
i hope this information is help you.

Changing the IMEI on a handset is illegal in a lot of countries, even if it is just changing it back to the original IMEI... There is Pro equipment available that can unlock these and correct the IMEI, you can purchase equipment like NSPro box to do this, or you can take it to a shop who may do this for you, however as I said it could be illegal depending on where you are and you will probably end up paying more than how much it would have cost to unlock the handset... There arent any codes that allow you to change the IMEI number back

You could try go to the phone service provider that you wish to use.
They may be able to assist you.

You may try default phone and security code to remove restrictions.
ur defalt phones codes is 12345 or 00000 u can use it
Default 4 Digit user code: 1234 or 0000
Default 6 Digit Security code: 123456 or 000000

Type *#06# at the mobile screen to know IMEI no of your mobile.
send the IMEI no to me and i will reply you with unlocking code.
IF Problem not Solved So
Please New Software install in the Phone Problem will Solved

The following worked fine on my Samsung SGH-G600 which was on 02 and now can be used with any sim:

*7465625*638*00000000*00000000#
NEXT ENTER
#7465625*638*00000000#
AND THEN *#7465625# to check the locks....all locks are inactive...these are all the locks...
network lock - inactive
subset lock - inactive
sp lock - inactive
cp lock - inactive
sim lock - inactive
activa lock - inactive
phone lock - inactive
auto network - inactive
auto subset lock - inactive
auto sp lock - inactive
auto cp lock - inactive
auto sim lock - inactive

JohnJ

switch the phone on without a sim card,
type in *2767*2878# WAIT for it to reset,
once it boots up itself, the phone code is now gone,
if the phone is asking for a SIM LOCK password
then send it to someone who has the equipment to unlock it

okay what you can do....is eprom it by pressing *2767*2878#.....this will also blank all data you had save on the phone.

People keep saying NSpro 3,7 to solve this IMEI reset problem in internet. However, NSpro 3,7 will cost you USD 169,99!!!! You can buy another NEW samsung mobile phone with this amount of money.