Personally I had trouble with the fuel pump relay connection on the board. The welding was broken so I had tension on the pump but no power.. The problem has been solved by simply dismantling the box and renewing the welding.. (All welding with power by the way) then new varnish on board..and back on the car!
Cost: 3 hours of work..for many years of happiness... so try this before supplying a brand new one...