The weird part is.....I've had it happen on 3 out of 5 stock TX's of which one stock TX just completely burned out (throttle side). To make a temporary clean, shoot contact cleaner into the pots where you see enough gap to get it to go in, and cycle the pot several times. It sould dry leaving no trace before applying power to the TX. I suppose if you had to...drill a hole in the pot casing being careful not to hit the mechanics so you can get the cleaner in there. Running the batteries below a certain point on these stock TX's will also ruin them. A DX6/DX7 is the best solution as you mention and adds another $200 to your investment but as you say... you can fly many aircraft on one radio...just buy more RX's which are less than the price of a stock TX. I found a DX6 on EBay for $149 shipped which included the TX, and AR6000, battery, and charger which is all you really need.

And YES....anything that can go wrong with these heli's.....I've seen it at one point or another, which I guess makes me an authority on the Blade CP series AND the HBKII....pay attention Gene (LOL).