You need to trace the problem. If you have time, try and see if you have a blown speaker. A blown voice coil could cause a ground, which then shuts down the amp/audio in the radio. Now a blown speaker may even play fine....when working so the only way to pinpoint would be to disconnect all, then hook up each one, one by one, while playing a low frequency signal, like a bass disc. The reason is that low sounds will cause max excursion in the cone, and will most likely reveal a blown speaker. If this does not solve the problem, check for rubbed/exposed wire behind the deck. While it's out, check the plug and see if all pins are straight and if it's plugged in securely.
Do you have anything connected to the radio like an Ipod, MBC/EBC etc....?
First and foremost though, replace the radio fuse, ususally a 10 amp and see if the problem persists.