allright... the spoilers that come up during maintenance are locked with retainers. On some aircraft the spoilers will remain up due to resistance in the actuator, even without hydr power. On the 757 they will remain up for a while; same with the elevator there that remains neutral after hydr shutdown, but goes down by time. A strong wind can blow them down, so it is still recomended to guard the spoilers if you work on them.