RouterBOOT reset button has three functions:

• Hold this button during boot time until the LED light starts flashing, and release the button to reset the RouterOS configuration (total 5 seconds)
• Keep holding for 5 more seconds, LED turns solid, release now to turn on CAPs mode (total 10 seconds)
• Or Keep holding the button for 5 more seconds until the LED turns off, then release it to make the RouterBOARD look for Netinstall servers