Reset Google FRP Lock using combination rom method

1- Download appropriate Combination file according to your device

        binary U1.U2... etc

2- Flash full combination rom using Odin or any Tool ( EFT Dongle)

 (in some cases like model J400F , after flashing combination you can enable oem and flash full stock       firmware)

3- Put device back in Download mode and 

    Flash ONLY boot +recovery+system from Stock firmware 

4- Now your device must boot up on desktop , enable OEM and flash       full firmware again .