How to fix iPhone 3GS power button without replacing?

I have repaired several iphone 3g and 3gs power button/headphone jack assemblies due to one or more of the buttons not working when clicked. Very often the power button is what doesn't work. Every time I take the phone apart, the power button looks fine although it's unresponsive. I'm pretty sick of replacing the entire assembly all the time for such a small problem, so I was wondering if there was a way to fix the button without replacing, such as taking the button itself apart into the metal discs and reassembling. If anyone has accomplished this feat please share! It would save me so much time!