I have a tablet with android 4.2.2 installed on it.

I was able to connect this tablet to my laptop before, but recently when I press the Turn on USB storage button, android restarts!

My laptop op is Ubuntu 14.04 TLS

What is the problem and how can I fix this issue?

  • Did you enable restart on "unauthorized" USB connection? Also what tablet? Custom or stock ROM? Debugging turned on? Can you access through ADB? – HasH_BrowN Jan 4 '15 at 16:53
  • How can I check this "restart on unauthorized USB connection" option? I can not find it. My tablet is ACME TB709-3G. Debugging option is not available in my settings!!! – S.Yavari Jan 5 '15 at 12:08
  • Goto settings>about phone/tablet scroll down to bottom and tap on "build" 7 times. Back once to main settings page. Scroll to developer options. Check your setting in there. – HasH_BrowN Jan 5 '15 at 14:17
  • Ok. Debugging is turned off and I have no option like "restart on unauthorized USB connection" there. – S.Yavari Jan 6 '15 at 2:56
  • @HasH_BrowN Athar can't comment(posted it in an answer) but wants to say, I assume to you: "There is no such option like "restart on unauthorized USB connection' in Developer options. My phone is rooted Micromax canvas 4 A210. 4.2.2 Jellybean." – Firelord Jul 15 '15 at 9:32

options for fixing USB not authorized

(On device)

  1. Go to settings/about device, scroll to "build"

    • Tap on build 7 times to enable developer options

    • Back out to main settings screen, goto developer options

    • Enable USB connection


(On device)

  1. Using a file manager that has root access

    • Remove "adb_key"


    • Reboot your phone and try connect again.

    • The confirmation message should popup after a short time.


(On PC)

  1. Remove the "RSA keys" from SDK settings


    • Start up ADB

    $ adb kill-server

    $ adb start-server

    • Plug device back into USB port (not hub) and wait.

    • Confirmation notice will popup after a short time period.


  1. You can try this. The steps are more involved, requires device and vendor IDs

    • this has been included because it is helpful and a reference

    • steps haven't been included in the answer because it is off topic

  • in step 3 (~) is the location of your SDK installation

  • make sure you have the latest adb executable installed

  • make sure you have the latest drivers for your device

  • make a backup before performing any of the above steps

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