Not sure if yours works the same way as mine does. All four of my slides are powered by electric motors. If you look in your storage bay's looking up do you see the slide- out motor's or shafts running parallel with the slide out? Do you see a long square shaft (or round) connecting to a motor that looks something like this?
or do you see a gearbox assembly that looks something
You might be able to get a wrench on one end of it and bring it back in. it's going to be a slow process so be patient. If you lift the master bedroom bed up and remove the board do you see an electric motor or gearbox something like the above pictures? If it were me I would see if I could find the electrical plug and un-plug the slide out just in case it gets a power serge. you don't need the extra resistance on the slide out when you are trying to bring the slide out back in. It could be a faulty switch or there is a lose connection somewhere? I would start in the most obvious and look for a blown fuse. Being the fact you said that only one of the four slides is working I would think that each slide could be on it's own fuse. I truly couldn't see the RV manufacturer wiring all the slide-outs on one fuse. Double check all the fuse's in the fuse box? If you get it pulled back in. Let us know what you find.