Edwin,
While I do not know Starcraft specifically, but most pop-ups use a cable system. Jams on the winch drum are common. Get the cover off the winches and look. There may be two in the front and two in the back. But a mis-wrap on any of them may jam the system.
If you find this, use cut 2x4 to to block the top at what you can reach and then back off the cables until they can be re-wrapped to feed correctly. This will be a greasy job.
Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.