May want to check the uphaul...
...to see of it's still on the sheave. I had similar problems last summer and noticed that the line had come off the sheave (at the cb casing) and was jammed between the sheave and the screw down table top (if you can call it that) - which created a lot of tension on the line and started to abraid it a bit when I was uphauling. Fortuneatly I was able to catch it in time before any real damage was done. The cb weight was enough to persuade it into the down position, and a lttle muscle persuaded it back up.It's a pretty simple mechanical system, so if anything were to feel wrong, that's the first place I'd check. Resetting this (and adding a little oil in the right places) made it much easier to move. Bill and Nancy also have good advice about point of sail - it's much easier to move up when there is minimal lateral pressure on the cb.