I have had this situation before, and mine ended up being a bur/catch on the nylon cylinder. It got stuck up a few times at the top and eventually wore out the motor. No manual release, once I got it to a point that I could lower it (certain amount of pressure on the water, it wouldn't go up again. Ended up having to get it rebuilt under warranty.
2015 Skeeter FX 21
...and down goes PhotoBucket with the new Terms of Service... I predict they will be out of business or begging for forgiveness inside a month. 6/30/2017