To install a firmware update, your ZERO needs to be in update mode. Normally you would do this via Settings → Firmware update.
If for some reason you can’t do this, for example if you haven't yet set up a wallet, you can also activate update mode by using this power button combination:
- Press the power button 2x (fast, like a double click), and keep it pressed the 2nd time until the red LED starts blinking. It will turn green at first, but just keep the button pressed in.
- Then confirm by pressing the power button once more and keep it pressed in until the red LED stays on. This means you activated update mode.
You can also activate update mode with a power button combination