Nexus 5 showing `device offline` when using `adb shell` command

Question

Issue: LG Nexus 5 is showing offline when using adb shell or adb devices command via CMD on Windows 7

Prefix to issue: Was unable to install drivers at the beginning - This has been fixed and when the USB Mode is in any mode (MTP, PTP, Charging) the phone is recognized and the drivers show installed on Device Manager.

I initially was having the issue mentioned in the prefix, however I was then able to fix the driver issue, which enable me to root the device.

After rooting: The device wasn't being recognized and I had changed multiple USB ports without any luck. After a day of this none-sense, finally got the device recognized in all modes MTP, PTP, Charging, Powered Off (charging - separate from phone being on and choosing Charging for USB mode) and in BootLoader mode.

Problem: When phone is ON, USB Debug mode is ON, and USB mode is set to MTP - this is how i rooted device, adb devices command. I have ran command adb kill-server then adb devices and it shows the device but showing "offline". Same when using the adb shell command - keep in mind adb kill-server command has been done in between any other adb command to ensure clean execution of the command.

Additionally: I attempted to "Revoke USB debugging authorizations" in different modes, changed USB ports and restarted my computer and device multiple times, however I do not get the RSA authorization pop-up on the device when connecting it to the computer.

Note: I have found different USB ports also give me different results, ranging form device completely being recognized in all modes to being only recognized as an "Unknown Device".

Journey: I have done extensive searching on the web, have tried easily 30-45 different posts with fixes that have worked for others, driver re-installations, most up-to-date software, multiple device reboots, tried multiple USB ports, and been trying to figure this out for several days and I cannot figure it out for the life of me!

Please help!

Answer 1

Solution: On LG Nexus 5, one must ensure that both the USB debugging mode and the USB Selection mode is set to CHARGING.

Ensure to delete adbkey and adbkey.pub from your ~/.android folder. (This folder is usually in C:\Users\username\.android)

Perform adb kill-server then adb start-server then adb devices on Command Line terminal. See: ADB Command

USB Selection Mode: When you plug the phone in, swipe down on screen and you will note Charging mode, listed as the last notification item. Ensure it says Charging - if anything else, simply tap and choose Charging as the mode. See: MTP Mode

IMPORTANT: You must install all drivers in all device mode. The USB cable must be connected to the phone and computer at all time.

1) If the device is ON and on the standard operation state, ensure both Nexus 5 and MTP listed devices in Device Manager is installed. The MTP should be loaded as Android Bootstrap Loader driver/device.

2) If the device is OFF, ensure the device is detected and the driver is installed.

3) If the device is in debug mode (when phone is OFF, hold Volume Up and Down button simultaneously and press the power button until you see the screen showing START), ensure that the driver is installed in that mode as well.

In each mode, the device is detected and Device manager will refresh to show the device detected.

Congratulations: Your device should show up as device when you run adb devices command.