Ps3 optic cable not working

Hello,
A year ago my blue-ray and cd sound worked fine. A year later (having not used the system), i can't feed my amplifier using the optical cable anymore.
Any ideas please?
i spoke to sony and they said it was probably the optical cable. it is in fact new. and there was no software or hardware problem that they were aware of

If you removed the optical cable and bent it before storing, there may have happened an internal break in the fibers of the cable. Even if you did not remove it, you may have otherwise damaged the cable. Therefore, it should be very easy to replace the cable with a good one. You can even borrow the cable from a friend for test purposes.

I do not have a PS3. Therefore, I have no idea if audio output can be set to not output through optical, but you should check the audio settings of the PS3 to make sure that the audio output is set to optical rather than to HDMI, etc.