As stated above, those things are most likely the reasons for it not working. The motor circuit has a built in overload on it, so it will reset after a few minutes, but don't keep trying to extend it until you do the above suggested things, you can burn out the motor, then you will play heck in getting another one, the parts to fix these assemblies are almost non existent to find. Shoulder bolts which hold on the locking mechanism should be available at any good fastener supply house, HD & Lowes won't have them. 3-in-1 machine oil is the lubricant of choice on the screw drive threads and bearings. Wipe off the excess and do that maintenance every six months, then you wont' have any trouble again. When/if you have it towed, make sure you have the tow company put the RV on a low boy, and if they insist on towing it from the front, disassemble the electric motor and the extend mechanism first because it will be torn off and you will never find the parts to replace it again as I understand it.
Monty & Janet - 2007 Alpine APEX 40 MDTS
S/N - 75715 - Retired - Master Certified RV Tech