Singer Sewing Machine Not Picking Up the Bobbin Thread?

I have a Singer Patchwork sewing machine. The spool of thread ran out. I put a new spool on. I checked to make sure everything is threaded properly, but still the bobbin thread will not come through. I even changed out the needle which didn't look bent. The needle goes up and down, but does not catch the bobbin thread. Could the timing of the gears go out of sync when I ran out of thread? How do I fix this or do I need to take it to a repair shop?