What causes a 5810R not even to power on?

Assuming you checked for correct input power, the main board or display boards could have failed. What serial number is the unit?

Serial #: 0033613    I have traced power to the main board, but keep reading there is an overcurrent device which might need resetting.   It is supposed to automatically reset once main power has been removed for about a minute.   I assume it might be somewhere on the main board, but have not located it yet.   Am thinking it might have failed.