[Nexus 5 Q&A, Help & Troubleshooting] rootintheair:
Hi everyone, I would like to share my experience regarding two methods that I have used to revive a Nexus 5 whose power button just will not work. Please use this guide if your Nexus 5 dies due to a low battery and you want to boot (start) it without power button. Following methods have been successfully tested on Win 7 and 10. You can use this guide and keep using your Nexus 5 without repairing the power button. There are other guides and posts which can help you attain locking, unlocking of the screen and remapping the hardware buttons such as volume keys to perform as a power button.

Method 1

Step 1: Download adb/fastboot binaries or use Android SDK for adb/fastboot. If downloaded as a zip, extract it in a folder. It is better to download adb/fastboot minimal, as it is small and can be handy.

Step 1a: Download your phone drivers and install them. If it is a zip folder then extract it in a folder for later use.

Step 2: Plug in the micro USB in your phone. Hold both volume keys on the phone and while holding the keys plug the USB cable in to your PC’s/laptop’s USB port. Your phone will reboot in Bootloader mode where you will see START written at the top of your phone screen which is the prompt to start the system but you cannot select it, as your phone’s power button does not work.

Step 3: Open Command Prompt in windows, which is cmd . Navigate to your adb/fastboot folder which you created while extracting the zip or you might be able to use the commands from anywhere in command prompt if you have installed Android SDK.

Step 3a: Commands only work if you installed adb/fastboot correctly or you are in the binaries folder. While in the corresponding folder,

Type: fastboot devices

123456789 fastboot

The command will show devices connected in fastboot mode just like the above example

If your phone does not appear here then go to control panel>device manager search for any unknown device such as unknown device or android device ; Right click on it and choose update drivers. Do not select the auto search for updated drivers. Select browse my computer for driver and then browse to the folder where you had extracted the drivers choose the right folder and windows should install your device as android bootloader interface device.

Once installed properly, you should see your device by typing the above command again. When successful

Type: fastboot reboot

Now your phone should reboot and start normally.

Method 2

Step 1: Download Wug's Nexus Root Toolkit by Wugfresh.

Step 1a: Download your phone drivers and install them. If it is a zip folder then extract it in a folder for later use.

Step 2: Plug in the micro USB in your phone. Hold both volume keys on the phone and while holding the keys plug the USB cable in to your PC’s/laptop’s USB port. Your phone will reboot in Bootloader mode where you will see START written at the top of your phone screen which is the prompt to start the system but you cannot select it, as your phone’s power button does not work.

Step 3: Run Nexus Root Toolkit. Let it complete its initialisation and when done its main window will pop up on your desktop. If your using it for the first time it will ask for your phone model and android version. Input the details appropriately, if you do not know the android version you are running choose any build which is at the end of the list.

Step 3a: The toolkit might ask for any dependency files to be downloaded, which it will download automatically. You might be able to skip it but if you use any build or wish not to download them but it won’t harm if you download them as you might wish to use the toolkit later.

Step 4: After completing the above step. Toolkit will finally be ready to use. From the main window of toolkit click Launch under the Advanced Utilities.

Step 5: Choose Reboot System and your phone will reboot normally.

If Toolkit returns, No adb/fastboot device found then follow the next step.

Additional Step: Go to control panel>device manager search for any unknown device such as unknown device or android device ; Right click on it and choose update drivers. Do not select the auto search for updated drivers. Select browse my computer for driver and then browse to the folder where you had extracted the drivers choose the right folder and windows should install your device as android bootloader interface device.

Once drivers are installed, go to Step 5 and it should work for you.

The above methods have been used on Nexus 5 and might be helpful on other Nexus or completely different devices from other brands

For Mods: I have done my good faith search before making this guide. Please let me know if a similar guide exists or I have posted it in a wrong place.

If it has helped anyone please consider a Thanks. By the way it is my first post. :)

For downloads, please use search engines and you will be happily served.

No responsibility is taken, whatsoever.