Gennie intellicode will not open door

[Awaz]

When I try to open the garage door, the screw will rotate but the carriage slips and makes horrible noise. The door will not come up. And when I manually open it; engage the carriage and then hit the button, it will go half way and then disengage, almost slamming the door shut. I am guessing it is a worn carriage, but wanted to make sure thats what it is. It is weird that all of a sudden it did this - no warning or nothing. Also, another thing I do not understand is that the door is a bear to open manually by one person - almost need two person. I am assuming this is because it is an insulated heavy door. I did look around to see if the cables on the side are being obstructed or the tracks have issues, but I did not see anything.
Any suggestions will be appreciated.

[Awaz]

I finally took the carriage off and saw it was stripped. I saw that it was a 1/2 HP motor and my garage door is a double insulated two car garage door. So, I just went to Home Depot and bought one of the Direct Drive Gennie motors (DC I believe). They have life time warrenty on it. That motor is freaking awesome !! It is so quite that you only hear the garage door coming up - no motor sound what so ever. And it will pull open that monster of a garage door with freakish speed !! I am a happy customer with that motor ! Recommend for anyone !!