BTW, the idea that opening up a TX automatically voids the warranty needs to be explored.

The instruction manual that came with my Futaba has a section that explains how to tighten the gimbal springs and suggest replacing them with stronger ones if tightening isn't adequate. I also notice that the case screws, that years ago were "sealed" with paint to indicate whether or not the TX had been opened, are not sealed nowadays. I would suggest that opening the case no longer affects the warranty at all.