The above are good tips. And you can of course look up the manual. Plus if it's still sticking. Inspect the whole unit visually, preferably with a camera
with both optical & electronic magnification, mounted on a tripod. From a couple of different angles; both close to the boat/from underneath, & from a good distance away, so that you're shooting closer to parallel to the horizon.
The contrasting angles will let you see a lot more.
The reason for the camera's semi-obvious. It's so that you can share pics with; riggers, your neighbors, us, & also study them later on on a high resolution screen
. And also, that way you have a visual record
which you can go back to later as well.
You also should remove the jib
in order to determine what's going on. Even when you get it to working properly. So that you can give the foil & the stay a good looking over. Particularly for things like loose joints, & fasteners coming adrift.
And it can't hurt to do the above, & or, go aloft to inspect things (along with the optical survey). Even after you get it working. As usually when one thing on the mast
obviously needs TLC, there are 3 more which could use it as well.
PS: If you go aloft, take the camera
with then as well. Especially for lots, & lots of pics of every bit of hardware
up there, from multiple angles. To include the masthead when viewed from above. Achieved by holding the camera over it, at arm's length. Unless, that is, you have a primo mast
climbing rig which allows you masthead access yourself. Unlike common bosun's chairs.