1) Download QPST
2) Install QPST and pin it to the Start Menu
3) Download LG Drivers
4) Install LG Drivers
5) In the phone’s Settings -> Applications -> Development -> enable USB debugging
6) Access the phone's hidden menu using the phone keypad (dialer), enter: 1809#*999#
7) In Port Setting enable CP USB (do not enable Retain ...) then press: OK
8) Plug your phone into the USB port and wait a few seconds until the USB drivers install.
9) Access the LGE Mobile USB Modem driver through Control Panel -> Device Manager -> LGE Mobile USB Modem -> Advanced -> Advanced Port Settings
10) Click on the box next to “Append to Log” so that a checkmark is in that box.
11) Click on: Query Modem
The window above “Query Modem” should fill up with (the following data is from my phone, your phone’s Revision may be and IMEI will be somewhat different):
“ATQ0V1E0 - OK
AT+GMM - 0
AT+FCLASS=? - +FCLASS: (0-1)
AT#CLS=? - COMMAND NOT SUPPORTED
AT+GCI? - COMMAND NOT SUPPORTED
AT+GCI=? - COMMAND NOT SUPPORTED
ATI1 - Manufacturer: QUALCOMM INCORPORATED
Revision: M6600A-SCAUTNZ-2.0.9720T 1 [MAR 11 2012 10:00:00] MP:TRULGE_08.09.02R_MDM
IMEI: 0127XXXXXXXXXXXXXXX (I’ve X’d out my IMEI for security reasons)
If that doesn’t happen, then the Port Setting has probably reverted back to “AP USB” and will need to be changed back to “CP USB” or the LG drivers didn't install fully or correctly or the computer's usb connection or the usb cable has a problem. Check the phone’s screen and see if the Port Setting is still at “CP USB”. If it’s not (back on “AP USB”) redo step 7. If the setting is still at "CP USB" then reinstall the LG drivers. If there's still a problem, it may be the computer's USB port or the USB cable.
12) Click on: View log
The phone’s current IMEI is listed in the information.
a) If the IMEI is the same as the original one, that means it hasn’t really changed from the original IMEI and it should be OK after the phone is reflashed with a .kdz update file. Flash the phone with a .kdz file by using the offline method.
b) If the IMEI is not the same as the original one, that means it needs to be changed back to the original one.MOD EDIT: IMEI changing is illegal in most countries therefore the instructions to do so cannot be posted on this site. Sorry for the inconvenience