No sound from Hi Fi ?

I have an Isymphony M100e Hi Fi, however there is no sound from the speakers. Everything else seems to be working perfectly, all the buttons, lights etc. If I plug in headphones, I can hear the music playing normally. Connections/wires to the speakers seem to be fine, however there is no sound from both speakers which were both working perfectly previously and stopped working at the same time. I would be very grateful for any help.