Factory reset when you cannot access recovery.
This method can be used if the device is no longer functioning at all and you may be succesful without connecting by a USB cable
1. Turn off the device if it is turned on, and connect it via USB cable to your computer
2. Press and hold the Volume Up, Volume Down, and the Power Button at the same time for about three to four seconds to turn the device on, if done correctly you’ll see an Android lying on its back (this may prompt a driver installation on your computer, so let that driver install before you proceed if so. If you need the driver, download a zipped copy Here
3. Use the volume buttons to navigate to the Recovery Mode option, and press the Power Button to confirm your choice
4. The device will restart, and after a few minutes the device should boot to a screen showing an Android with a red triangle, press and hold the Power Button and Volume Up on this screen for about two seconds and let go to make the menu options appear
5. Use the volume buttons to navigate to Wipe Data / Factory Reset and press the Power Button to confirm your choice
6. Use the volume buttons to navigate to Yes and press the Power Button to confirm your choice