Mickey2

The 930 model has a lot of marked off oil points, like Joe mentions, tend to them all with a a drop or two of oil. Can you se anything behind the faceplate? I think you have to take off a screw to get to the bulb, and maybe you have the preser lever and bar in view there? You might have to inspect them from the top, by lifting the top of the machine. There is a large flat set screw there, it's the presser bar tension (top of the presser bar); try to inspect what goes on further down there. There might be some auto fuctions interfering, I don't know the 930 model that well. Make sure the buttonholer knob is set to zero, try and slip some fabric under the presser foot and wham it at full speed after you have oiled it (start of carefully). The fabric is to protect feed dogs and presser foot a bit. Take it out on a table in a heated room, give it some gentle care the next few days, try to wiggle the parts involved now and then, test sew a bit. It's often all that's needed to loosen parts and get it going again. It's at least first step, since you know it worked well before it was stored away, my guess that exactly what it needs.

Remember to take out needle and presser foot before you attempt to take the top of the free arm off. The paint so easily get scratched with them in place.