I have a Duo-Fast electric stapler model # T.E. 3320. Are there 3/8 staples for it available now?

SOURCE: Swingline Stapler Staples Only After You Open It Up....

When you lift up the top of the stapler (as though you are going to put staples in), does the pusher slide freely back and forth? It might be getting stuck at some point and not pushing the staples (either due to a worn pusher spring, or friction). First (after removing the staples) try spraying some light oil on the mechanism and lifting the top part of the stapler up and down a few times and observe how easily it moves back and forth. Also, with the top open try GENTLY sliding back and forth a little - if it slides fine with no sticking, try loading staples and using stapler. If it slides ok, but doesn't quickly return to it's "normal position" when pulled so as to put tension on the spring, rhen the spring may be worn and need replacing.

SOURCE: Nothing happens when you load paper to staple.

assuming it is plugged into a good power source and turned on (no offense intended, just getting the obvious out of the way - and I've fallen victim to the obvious myself before), look inside where you put the paper - is there a trigger mechanism? Most electric staplers have them (the paper hits the trigger and the stapler fires), and some allow you to set the sensitivity of the trigger. If yours allows you to adjust the sensitivity, try adjusting it. If it's not adjustable, the trigger probably needs to be replaced (under heavy use, they may need to be replaced every year or so).

SOURCE: Disassembled the stapler now need diagram to reassemble

Found user manual online but no parts breakdown, I have a phone number at 1-800-343-9329 and they might be to email you the breakdown. Wish I had better info but this is all they furnish online.

SOURCE: Staples penetrate, but do not bend

If you unscrew 4 bottom screws to lift the top cover, you may find out that there are 2 orange rubbers above its hammer that broke and needs to be replaced.

SOURCE: I need staples forthe swingline electric stapler

Go to Lowes or Ace. Take the stapler or an empty box along.