https://flameboss.freshdesk.com/support/solutions/articles/14000136923-how-to-remove-the-magnetic-base-on-an-fb500-to-view-serial-number
How to Remove the Magnetic Base on an FB500 to View Serial Number : Flame Boss
how to remove
https://flameboss.freshdesk.com/support/solutions/articles/14000101384-fb200v2-fb300-or-fb500-controller-no-longer-connects-to-wifi
FB200v2, FB300 or FB500 Controller No Longer Connects to WiFi : Flame Boss
no longer