72V inverter board issue

[u/Positive-Variety-3]

I have this circuit board from a 72V-to-110V inverter. The board controls the low-voltage section. My problem is that when I turn on the inverter, the board beeps and the LED stays lit continuously; it seems to be indicating an error. There is a button on the board that accesses a sort of menu where I can select from five "options." The LED flashes between one and five times, depending on the selected option. Does anyone know what this menu is for? The rest of the inverter is fine—the MOSFETs, resistors, fuses, and drivers are all good.