Chances are the recoil spring may have broken. I repaired a bunch of springs from outboards, lawnmowers and a blower.
They are a PIA to repair, but if your careful and patient it can be done.
The spring usually breaks at the end where it attaches on the inside.
The springs can be very tightly wound, so gloves and eye protection are recommended.
Once it's apart you'll have to figure out the best way to repair. I've always been able to modify the existing spring.
A repair manual or at least a parts diagram will help.
A vise and various pliers including vise grips will come in handy.

I dought the owners manual will do you any good. usually they don't cover that problem. Sometimes the winder get stuck at the end of the pull, you may just need to manually push the winder to free it up or move the crank unbinding it. This happens on my cheap weadeater blower and I just cut a hole in the bottom to get to the flywheel nut and use a deep socket to move it and the winder spools back in. I guessing the winder is most likely rubbing something causing it to stick if edscre not right about the spring breaking or pulling loose and releaving the tension on the winder?

Good point from rcmoser, I'd make sure something isn't bound up or jamming the mechanism before taking it all the way apart.
Their is also a part(s) that allows the engine shaft to freewheel on the starter pully. That could have a problem or be stuck. A little judicious hammering could free it up.