Dog Shock Collar Remote

My neck of distance learning is suddenly not working?
It is a spray collar, a shock collar. Petsafe Remote Spray Trainer, if necessary to be exact. I have it again yesterday and tested. He lit, filled, loaded, went through all the functions (not my dog or myself, as it is) worked great for everything. But today I went to use and the role of aerosol stopped working. It emits a positive and negative tones and lights, but when I try the spray (not matter what configuration, there are four "levels") that fits only. It is assumed that a flash of light that indicates it's working and it does do that, but not spray out. I loaded up again, reset it, refilled it, and nothing. I have not dropped or wet, scratched it, kept him in a very cold place / Heat, or covered with anything. Thereza Someone happen to know what could be wrong?
They said they were useless ….
35-01104-101 327 Dog Training Shock Collar Remote Control For 2 Dogs.flv