first check the battery voltage with a volt metor if it is below 12 volts charge it and if that dont work check if the mower is in gear or blades are on if that dont work find your mowers safety switches you can go online and get a wiring diagram and look there or look up where they are on youtube or the general area i suggest looking is on top of the trans and for the mower deck follow the deck height lever down and look for wires and what you looking for is a button that is either stuck on or off clean the switches and try again if that doesn't work i say try and find the starter solenoid and check if that is bad there are hundreds of videos on how to check it. i hope i helped