I've got ASUS ZenPad C 7.0 (z170cg) and I'm using Debian 8.2. adb is working fine, but fastboot does't see the tablet. I want to unlock bootloader, but I am not even sure if it's locked (device in bootloader mode only show running android on the green background and nothing else). 'sudo fastboot devices' doesn't show anything and 'sudo fastboot oem unlock' is giving me only < waiting for device >. To get in bootloader I'm using 'sudo adb reboot-bootloader'. And if it's important, I am using adb and fastboot from debian packages 'android-tools-adb' and 'android-tools-fastboot'