Picked up my impact wrench (1/2") and it stopped working. Pull the trigger and all you get is air out of the exhaust. No rotation.

Is this worth tearing into? Could something be gummed up, not letting air flow to wherever? I'm generally good at fixing things but I've never been inside an air tool.
All advise appreciated. BTW, the gun does not have that many hours on it. 9 years with maybe changing two or three sets of wheels per year.

Thanks,
Ivan Vegvary