Your restricted electrical licence, must be very restrictive, as the first thing you should be looking for is a fault else where other than the circuit board.
I would guess something has shorted to ground or a direct short between active and neutral.
Tracks dont just vaporize as fuses for no reason, and the track only goes to a relay set of contacts, so i fail to see how the problem is on the board, well not the initial problem anyway, there might be other damage to the board now, but the inital problem still remains off the board.
Pete.