# Hardware test mode

> Exercise the LEDs, the buzzer, the display and the printer in one pass from the keypad.

- **Page** - https://iotready.com/docs/hardware/troubleshooting/hardware-test-mode
- **Book** - [Hardware](https://iotready.com/docs/hardware.md)
- **Section** - Troubleshooting

Press **Enter Key** + **9** to start the **Hardware Test Mode**.

## Event sequence

- LED lights light up: green, blue, red.

- Buzzer beeps.

- LCD is filled with characters.

- Label print is triggered.