Well the new glued on pad worked well for the Volume down button, but not so well for the Channel down button. It does work, but I have to hold it down for several seconds.

I think the reason could be the height of the silicone adhesive that I applied under the pad was too low, causing the button to not make good contact with the motherboard.

I do think that this technique would work well to repair non working buttons with some experience though.