What was found
CREW REPORTS AFTER ENG START, THE APU BLEED VALVE APPEARS TO BE STUCK CLOSED. WITH SW ON, NO DUCT PRESSURE AND APU BLD SW VALVE LIGHT IS ON, WITH SW CLOSED, NO DUCT PRESSURE AND APU BLEED SWITCH VALVE LIGHT STILL ON. CYCLED SWITCH NUMEROUS TIMES AND NO HELP. RETURN TO BLOCK. DEFERRED IN ACC, WITH MEL. REPLACED APU SHUTOFF VALVE PER MM, OPS OK.