Does anyone know how to fix a jammed Swingline large duty stapler? It ran out of staples so we took the spring out and...

It ran out of staples so we took the spring out and put more in (not too many), and in a minute it seems to be jammed. When I push on it to staple something, it goes down to the point where on earth I assume the staple is supposed to come out, and then nothing. We've taken the staples out and checked for jammed staples, and didn't find anything. Maybe it's simply time for a new one?
Answers:    Lumberg took my stapler and he never brought it back, they switched from the Swingline to the Boston stapler, but I kept my Swingline stapler because it didn't bind up as much, and I kept the staples for the Swingline stapler and it's not okay because if they lift my stapler then I'll set the building on fire...
Sincerely,
Milton
It sounds close to you bought the wrong size staples. The stapler will have printed on the side what size it takes. Those Swinglines don't break!