USB Debugging not working, adb ignores Nexus 7

Question

For several weeks, I was able to connect my Nexus 7 2 to my computer running Windows 7, and Eclipse would recognize it, allowing me to run apps on it. The device also showed up when I ran the adb devices command. Every time I plugged the Nexus 7 into the computer, the tablet asked if I wanted to allow USB debugging at that time. (Oddly, it never asked me whether I wanted to always allow it from that computer, but I didn't care.)

I recently updated the tablet to Android 4.4.2. I also updated the Android SDKs through the Android SDK manager. Now, when I plug the tablet in, I do not get prompt about USB debugging on the tablet, and neither Eclipse nor adb can see that it is there.

Here is a list of things I tried to do, gathering ideas from various forums around the web.

• Re-download the Asus drivers for the Nexus 7 and update the driver. However, Windows does not even recognize this as the right drivers for this device.
• Turn USB Debugging off and on on the tablet, and also revoke all USB debugging permissions.
• Change the connection mode from media device to camera
• Switch the runtime from Dalvik to ART
• Type adb kill-server followed by adb start-server in the command line
• Delete eclipse and all the Android SDK and download them all over again

None of this worked. Any other ideas on what to try?

Answer 1

It turns out that the Nexus 7 definitely needs the Google USB Driver. Finding, downloading, and installing this driver worked perfectly.

Because Google's Android OEM drivers page does not include the Nexus 7 in its list of devices that need the Google USB driver, I had been trying the driver from Asus, which did not work. I did not try the Google USB driver because for some reason my SDK manager said it had downloaded the driver, but the driver was not to be found.

Finally I found I could download the Google USB driver from this page, which clarifies that all Google Nexus devices need this driver. Now I have successfully re-connected the tablet to ADB.

I submitted a documentation bug report to Google here in hopes that the OEM drivers page can be updated to reflect that all Google Nexus devices need the Google USB driver.