How to hook up a aux cable to a sharp micro component system XL-UH242?

I'm trying to play music off my iphone throught the speakers useing a aux cable but it won't play even after i turn the stereo to aux

Assuming you are running a 3.5 mm stereo plug to red/white RCA adapter cable between the two items - it should be working. Of course make sure your iPhone volume is up and that the cable is connected to red/white auxiliary input in the Sharp stereo.

Once you have double-checked your connections and volume on the iPhone, I'd say the Sharp stereo is defective.