What will be the problem if speakers are not working?

-first check the wires tobe sure they are connected properly. Then check to see if you are on the right receiver channel and check for the mute feature. If that does not work try hooking the speakers to another device. Could be a fried receiver.this could be caused by a wide range of problems broken cable,broken input and could even be that the contact has come loose inside the speaker and needs re soldering (unlikely) the amp which i located inside the subwoofer could have blown due to many problems.The fuse for the plug or the fuse located inside the sub may have gone due to over volt or just vibrations or wear and tear hope these suggestions help if the speakers still have warranty send them back for repair or replacement
if they're home theatre speakers (like the catagory in which your question was asked) then its a faulty connection or a broken component in your speakers
The speakers are not working is the problem