was out in my shop and grabbed a 304 to test it on my system... hooked it up... no dial tone... Hmmm. so I decided to open it up and check.... upon opening it up I found a hole in the cap... so, I changed that out... took the whole phone apart and did a quick cleaning on it... had to change out the handset, thinking that maybe I had a bad transmitter or reciever... plus it was the wrong style for the phone... an F1 handset, but I think it came off a military phone ... anyway here are some pictures of what I have!