Hedge Trimmers

Poulan Pro Hedger PP2282 Blades Don't Move. It is one year old and was working fine. After using it one day and restarting it the next day, the blades no longer move. The engine starts fine and I can rev the engine but no movement at all from the blades. I have loosened and re-tightened the blade bolts and used WD-40 to see if that helped. At this point, I still cannot get any movement and don't see any obstruction that would prevent movement. Any ideas?

Thanks in advance!