Dmitriy Sinyavskiy. it is possible that something is just turned off. Go into your menu and find RESET, push it and try your flash again. You can also try it in aperture priority or shutter priority, sometimes auto setting wont allow flash unless you press a button. Let us know what you get. If it is hardware related it could be the bulb as well as the flash capacitor, however, that should trigger an error code on your camera.