Facing network or Internet related connectivity problems?
SIM not detected by the phone?
In some android phones such problems occurred after
flashing some rom, mod, scrip or software because
nvram of the phone corrupted or damaged by flashing software and
imei is stored in nvram of our android.
check your imei number by typing *#06# on dial pad.
If IMEI number erased, altered, damaged for some reasons then change/ edit/ fix/ repair invalid imei issue by editing imei number in engineer mode.
Disclaimer : This video and method shown here is for restoring the original imei number of android phone. Please remember changing original imei number or using any other person's imei number is illegal. TechTeam Sarvinsun in no way held responsible if someone misuses this method.
For S2/S3 and Note2/Note3:-.In the dialer , type- *#197328640# or *##197328640##*
ANDROID 4.4.2+ type this... *##197328640##* or try this ##197328640## or try *##197328640##
The actual code is *#197328640# (with no spaces in between)
 Open Phone Dialer and enter *#*#3646633#*#*.
By entering this you will enter 'Engineer Mode' of the device.
Note : "Misconfiguration in engineer mode can cause damage
 In engineer mode go to CDS Information
 Click on Radio Information
 Select Phone 1 for Ist imei (Phone 2 for IInd imei)
 At the top on command line type EGMR=1,7,"IMEI" after AT+
please type 15 digit valid 1st imei number within quote " as shown
here : AT+EGMR=1,7,"1234567890XXX15"
 Hit send command
Don't put imei without quotes. Wrong way: AT+EGMR=1,7,1234567890XXX15
Correct way: AT+EGMR=1,7,"1234567890XXX15"
please put imei between " "
Don't Ignore Special Characters
 For 2nd imei number type after AT+EGMR=1,10,"IMEI_2" (put your 15 digit 2nd imei number in place of "IMEI_2"
 Hit send command
This method is for mediatek device,can work on many chinese phones as well. Watch and resolve imei problem in mtk/chinese devices.
Codes shown in the video is tested on mediatek device and may work on many models but will not work for most of the models of samsung, (including samsung fakes), htc, sony, lg and some other manufacturers. You can easily find written tutorials with download links of necessary files in xda forum and gsm hosting forum by searching in google. Type "repair imei ...your phone model".
Some important links for Android Codes for samsung devices :
 Android Samsung Secret Code
 Galaxy Note Dial Pad codes
 Samsung Engineering Test Code
 Secret to Unlocking Jelly Bean Service Modes
Other important links for Android Codes and android applications :
 MTK Phones Dial & Secret codes
 Engineering mode codes and apps on Android 2.1/2.2
 Engineer Mode Test Tool
 MTK Engineering Mode
 Most Useful Android Secret Codes To Know