Shower panel repair : 4 way selector

If you happen to own one of those "Smart Panel" shower walls from Smart Showers (or another similar re-seller of China's poor designs) you may find that the flow destination (feature) selector switch is getting stuck. This kind of shower comes in different styles, but uses the same valves. You probably have one of those showers if you have at least a waterfall, hand shower and jets. Another tell-tale sign of this kind of shower is that the water temperature/flow selector is on the bottom with a