Why isn't the bass working?

Hi, I've had these speakers for a long time (Genius SW-J2.1 500) and they were working just fine but all of the sudden one of the speakers stopped working along with the bass. Sometimes if you turn it off and on the bass works again but just for a short period of time.

For example, if I get it to work and I'm listening to a song with constant bass it keeps working but after the song (or the bass part) ends it won't work again. Needless to say that turning it off and on rarely works.

What do you recommend? I could post pics if needed, but when I opened it I didn't see anything wrong inside. I'm not an expert so there's a high chance I'm missing something