title: Unable to connect Android device using adb
body: <p>I am connecting my Samsung Galaxy Tab to my macbook via USB.</p>
  
  <p>I used to be able to pulling file from my Galaxy Tab using adb but all of a sudden I can't do so. </p>
  
  <p>I can see my device using <code>adb devices</code>
  but when using <code>adb -e shell</code>, it prompt <strong>error: device not found</strong></p>
  
  <p>Device already turned on the USB debug mode. </p>
  
  <p>What's going wrong? Anyone can help?</p>
  
  <p>P.S. My galaxy Tab was running out of battery before, if it has anything to do with it (?) </p>