I don't think it's the switch. I had this happen to and I posted the questions here. When I took it apart, I found they the drop had caused a connector to pop loose. I think it was the one marked #5. It's a super tiny connector. I plugged it back in and everything worked. Might be worth looking at. The instructions are on here, just follow the instructions for taking it apart and look for the #5 connector to be loose. Go to the "Repair" section of this site and find the repair for the mute switch and follow those to take it apart. Look for that small plug and make sure it's plugged in.
I bought the button off of ebay for about $4. In the meantime, I found a post that had a close up of the switch and realized the button didn't "break", but rather the glue came off. I glued it back on. However, the problem with mine, above, is that that button stopped working, along with the volume control. I took it apart and found a connection had come lose. I plugged it back in, and now it works fine and I have my mute switch glued back on. However, if the glue fails, I still have the backup button I got from ebay. Very easy fixes.