[MeMO Pad 7 Q&A, Help & Troubleshooting] FrazUK:
It seems no matter what I do I can't get the popup to show to authorize my computer on the device. The device shows up just fine in adb but is unauthorized and I can't authorize it due to never receiving the popup. I'm using Windows 8.1 which is where I prefer to do my development but I actually installed linux and set up my environment there just to see if I could at least authorize the device but still couldnt get the popup there either!

Here's a complete list of what I have tried. They arn't in accurate order, i've listed them generally as I remember doing them...

1. First off i just let windows detect the device and install the driver. The device showed up in device manager as Asus Android Composite ADB Interface

2. I'm using Android Studio. I made sure everything was up to date. ADB Version 1.0.32, Android Studio itself fully updated and everything up to date according to SDK Manager.

3. Looked to Asus for a specific driver but there is no driver for this specific model.

4. Tried Google USB drivers. Had to force install

5. Tried Asus Android ADB Interface and Asus Android Composite ADB Interface drivers I found online. Had to force install.

6. Tried Asus PC Link hoping it would install the correct drivers automatically.

7. Rebooted pc and device many times as well as toggling usb debugging, revoking usb authorizations and switching between MTP and PTP. All of these were done in just about every possible combination with every driver I have tried.

After all of the above the device continued to either show offline or unauthorized. All these drivers seemed to work as the device was picked up by adb, but no authorization dialog on device.

8. All of the above was done under Windows 8.1 so at this point I said screw it and installed linux just to see if I could at least get the authorization popup to show. I Installed Android Studio under linux and performed all the necessary steps. To cut a long story short I did pretty much the same as I did in Windows minus messing around with drivers. Again under linux I could get the device to show but either as offline or with no permissions and still no authorization dialog.

9. I don't know much about linux, so had the help of a couple of kind guys on irc who walked me through some other things which im not entirely sure what they were.....something like adding android rules and registering usb devices manually with their PID and VID. lsusb seemed to show the device just fine.

10. Evntually gave up on linux as I hadn't made any progress at all and I was just getting the same problems as with windows 8.1. So at this point I went back to Windows.

11. Went back to the Asus site and grabbed a an adb driver for a simalar device (differnt model of the memo pad 7). I had a look in the inf file for this driver and found that my model was actually in there and got excited. Windows wouldn't let me install because of the file being corrupt or possibly being tampered with, so I disabled driver signature enforcement and windows happily installed them. This was something new as they were the first drivers that installed niceley since the very first one windows automatically installed. I'm satisfied now that I actually have the right drivers due to my model actually being in the inf file and the device is now being picked up consistently by adb. When it is picked up as offline all I need to do is toggle usb debugging and it gets picked up again as unauthorized...but still....

NO AUTHORIZATION DIALOG ON THE DEVICE....ARGGGHHHHHH!

Also I should mention, while doing this I also tried with a Lenovo device as I went through each step of trying to get the Asus to work and I had the same problem with the Lenovo. No authorization dialog. But how is this possible? 2 devices, multiple usb cables, 7 usb ports, Windows and Linux, Multiple drivers for each device etc etc.

I'm at the end of my tether here. I have been at this for about a week solid now and I am no closer to finding out the problem. Surely it can't be 2 problematic devices? But It can't be both Windows and Linux? Are all my USB ports broken? Are all the 5 USB cables I used (Official asus, official lenovo, official htc and 2 generic cables) damaged?

The only similarities here are that The pc remains the same and both devices are kitkat 4.4.2.

Please help!

EDIT: I now have 5 devices here. The Asus Memo Pad 7 ME170C, Lenovo 3500-f, Archos Gamepad, HTC Desire HD and a crappy chinese tablet off ebay (Allwinner A13). The latter 3 are running older versions of android that don't have the whitelisting feature and all show up with their serial numbers ABCDWHATEVER Device when running adb devices but as soon as I run android studio they go offline. The Asus and Lenovo show as ABCDWHATEVER Unauthorized (still not getting the authorization dialog on these two devices) and also go offline when running android studio.