Thanks for the post,

It's hard to say what the cause is specifically as I don't have the tool here to physically diagnose, but I'll see if I can help.

First, does it not make any sound at all when you try to fire it? Does it sound as though it's firing?

If you can give me a few more specifics on what's it's doing or not doing that would greatly help.

- MTR

I have to give you all the common problems being people have over looked thing in the past. So don’t take the first two the wrong way.

Common Problems:

- Ran out of gas

- Battery too low

- Driver might be in low position. If the tip of the driver can be seen by looking down inside the nose, the driver is out of place.
Remove the battery, use a long skinny screwdriver or long skinny punch and push the driver back up inside the tool. If the driver is too low, the combustion chamber is too large and the tool will not fire.

Attached are other troubleshooting from page 22 of the owners manual.

- MTR