Hi
surprised no one suggested slop/wear in the mechanical linkages....when going down the linkage is pulling the window and gravity helps, but going up its pushing and any wear movement will stall the motor...
You can try spraying some food grade silicon spray in the window channel (better than wd40 as it wont attract dust as much) with the window all the way down. If it improve then you may have to remove the door trim and check/grease the mechanism.....
If this were the case, just fix it properly, either via adjustment in door or a new reg. That said in 10 years I never saw a case where linkage wear was enough to completely stall the motor/gearing. These units can break your fingers, so more often the case was the front of the glass would drop, the rear top corner would visibly pop out. It would also happen in the same place, halfway up, when the channel changes from a full c bailey to the half channel that you visibly see around the door.
If the glass goes up and down fine (stays in the channel) when it's working, my money would be on electronics.