Do you mean pull it manually while the up-button is pressed?Try this it get someone to help the glass to go up while someone triggers the button see if it goes up. I hope this helps.
Thank you, I'll try to do that.Yes, that is what i meant. You have named a symptom that will pinpoint the problem. It must be the wires that goes to the door via the rubber hose. Try this open the door in a different angles see if stuff starts to work. You might have wires that are breaking.