becker,
There's a number of issues that plague those steps. As has been stated, a periodic lubing of all the pivot points is warranted to keep things moving as nicely as possible. Another problem of course is the small motor. They have lots of issues. They can freeze up due to corrosion (although it doesn't happen all that often) The brushes can get corroded over and will not have good contact with the commutator ring.
The gear box is also known to cause problems. If the gears in there are worn to a point that a tooth breaks off, it can lodge in between the drive gear and, the driven gear. The link-arm can get seized up in its pivot points too. The connections to the motor, although are fairly sealed up, can on rare occasion, also get corroded.
All of these various issues have caused problems to many folks. If I had to guess, I'd bet right now that your issue is not caused by the pivot points locking up. While it does make things work more smoothly when lubed, to completely lock up a set of steps because of non-lubing for a length of time, is not very likely.
The problem with your situation is, the steps are in the retracted position and, that makes for hard to get to components to be analyzed for correct working operations.
There is either a bent or, straight "link arm" that connects the motor to the gear box in your steps. What you need to do is, do the best you can to disconnect that link arm, while the steps are in that retracted position. Once that's disconnected, the steps will fall, due to gravity. Be prepared for that. But, once they're free from the connection to the motor and gear box, you can pivot them out of the way, so that you can start your analyzing of other components.
And, while you're at it, and, they're disconnected from that link arm, you can see just how free they move or, don't move. Good luck and please report back to what you find. Good luck.
Scott
Scott and Karla SDFD RETIRED2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad
2008 Caliente Red LVL II GL 1800 Goldwing KI60ND