android - Cannot connect to adb -

android - Cannot connect to adb -

i have tried connect phone ubuntu computer , nil working. have tried 3 different phones (mostly nexus 4) on mtp , ptp protocols. adb debugging on install unknown sources. have connected adb 1 time have never been able since then. adb usb, adb tcpip both device not found (all of these phone plugged in). adb devices shows empty. adb connect [ip] returns "unable connect [ip]" (i have adb on network enabled , works on other computers). when plug phone in doesn't observe connected computer no matter usb port try.

what else can seek connect it?

i outlined major troubleshooting steps making adb work in linux environment in write-up

use command list connected devices enumerating either adb or fastboot interface:

find -l /sys/bus/usb/devices -maxdepth 2 -path "*/modalias" -printf "%h\t" -exec cat {} \; | awk -f: '/icffisc42ip0/ {print $1}'

to see serial numbers instead of sysfs paths - add together | xargs -i cat {}/serial

android linux adb