iPhone 3GS silent switch won't work

[MADP55]

Switch to silent, and see lined bell. then a minute later unlined bell pops up, then toggles back and forth and vibrates. Bad in meetings when phone rings, even though it shows silent.
Blown air, toogled multiple times. Only solution is turn audio to zero.
out of warranty.

 

[SnapThrow]

The switch is replaceable

3GS Mute Button

Requires taking out approx 15 #00 screws but it is doable if you go slow and carefully, but it could be the ribbon cable that went bad

3GS Headphone Jack Assembly