If you have a 12v bulb from a car, say a sidelight or interior light rather than a headlight one, you could try that across the wires in the 4 pin connector to see if theres power there. Not sure what current they take so the lower wattage bulb the better but I would expect it to provide sufficient to light a 5 watt bulb quite brightly, may save you a trip to the pc shop.