Mine did the samething and I was in the process of changing it and had actually drilled out the rivets and for some reason it started working again,it happened a couple of times after that but not for awhile now. There was a pin in the front that had worked its way out that I put back in and I have remounted the motor with nuts and bolts. I do not think I did anything to solve the issue that I am sure of,but it works know,I also used lithium grease on the track which helped it on how fast it moves up and down. My passenger window does the samething at times and I have to hit the door for it to go up,it is almost like they have a limit switch that if you go to far it will not allow it to come backup. neither are doing it now,if it gets to be a big issue I will just replace them.
Marry the right person it will determine 95 percent of your happiness or misery. Remember that old saying,you can be right or you can be happy,I choose happy.
89 xj in progress D44,4"x 2" lift
72 Restored chevy truck 4x4,lockers,built 350,approx 400 hp.