How to get to the service menu or engineering mode?

[Shubhamlondhe]

Hello friends... I have recently bought Samsung galaxy grand prime device... but this device is confusing me that how to get to its eng. Mode or service menu... there r lot of direct apps which can take u to that section but none of them worked for my device... I tried lot of secret codes but they didn't work..
By the way I have Qualcomm processor and many apps are available for mtk but not for qc... so any ideas? Plz help asap..

 

[darthvader30]

http://joyofandroid.com/android-secret-codes-hidden-menu-dialler-codes/