Note to myself:

When I want to start my Sony #z3c installed with #CarbonROM in #recovery mode I need to to switch it off, disconnect usb and then push and hold volume-down and power together until I see #twrp starting.

remember:

• disconnect usb
• shutdown / switch-off the phone
• press and hold volume-down and power button …
• …until you see twrp booting

Don't try adb, don't try rebooting from CarbonROM into twrp - you didn't get it to work the last time you tried