Cannot connect to MangOH board after rebuild kernel

Hi guys,
Recently, i have rebuilt the Linux kernel with the source from SierraWireless. i downloaded the Linux distro source Release 17: [SWI9X15Y_07.14.01.00 Source] and built it. But actually, after i customize the image by menuconfig, built it and loaded to MangOH Green board, i can not ping to ip and also cannot see the USB connection when i use “lsusb”. Please give the solution. Thanks for reading

P/s: Please give me the solution to fix it or flash the wp85 module. Thanks guys