silent mode switch not operate

Hello,

the silent switch is not operating on my Ipad.

(the volume switch are ok)

So there isn't any sound with some application (TV for example).

and if there is sound (Ipod for example), I can't switch off with the silent switch.

I opened the Ipad to see the switch cable and it seems ok.

Please, could you help me ?

(Sorry for my english, I'm french )

Thank you