I have special device, that have no screen at all. Only 3 buttons: volumes and power. So the problem that I've used hard reset option and after that on all my computers I got error:

error: device unauthorized. Please check the confirmation dialog on your device.

The problem, that I can't check that dialog - no screen or input methods. I've tried to connect from recovery mode, but from it the same.

What can I do in that situation?

1 Answer 1


In Android 4.2.2, Google implemented Secure USB Debugging, aimed to prevent adb from being connected to malicious computers. The user has to authorize a computer before it can connect with adb.

The intended design of secure USB debugging, is that the user needs to manually to authorize new adb hosts. If the user attempts to use adb without authorizing the host, it will throw the following the mentioned error.

However, there is a bug on Android 4.2.2, fixed in Android 4.3.3, it was discovered that by navigating to either the emergency dialer or the lock screen camera, it was possible to trigger confirmation dialog.

All of this implies physical interaction with the device. So I'm not sure this could be possible without confirming the host. Try connecting it in a computer where you already confirmed the device.

  • It is Android 6 on the device. I am able to interact with device physically, but as I said, there is no screen on input method to do that. I've tried to confirm dialog with that three buttons, but nothing happens. Commented Dec 20, 2016 at 10:40
  • The buttons are not set to confirm anything. Physical buttons have their own purpose. Just get a new screen and a digitizer. What is the phone model?
    – esQmo_
    Commented Dec 20, 2016 at 10:49
  • As I said, it is not phone, screen is not broken, it's not exists at all :) Commented Dec 20, 2016 at 10:53
  • What kind of device it is? Providing more details will help us to help you!
    – esQmo_
    Commented Dec 20, 2016 at 11:17
  • It is typical Chinese device, so it is hard to get info from developers. It is exactly like phone from Android developer view but no screen (device purpose is ADAS and video recording so no screen is needed). Is there some way to solve that problem? Seems that it is not normal to get that kind of error in recovery, even if device after hard reset. Commented Dec 20, 2016 at 11:20

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