speakers how they work

I drive a 1997 Camry. my rear speakers do not work, I do not think they are blown Tho. What could be the problem?
everything is original speaker factory, factory radio so he could be on the radio? if it is a fuse, where would the FUS box and all be in radio?
your rear speakers are blown every time customers come with the same problem telling us they do not know why not stop it but yes they are bad at the same time and happends in the Camry and Avalon you need speakers
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