I guess Richard will know the answer : o) but otherwise I cd take a look at one of my spares at the weekend and see if the switches look like fixable - the rotary switch is just copper contacts, so possibly the temp switches are the same "technology". Do you have a wood surround on the HEVAC unit? that can interfere with the buttons if it is not completley lined up
HEVAC screen dimming is either the power, or could just be as easy as replacing the backlight bulb. You're sure you haven't simply pressed the dimmer switch without knowing (slider on the LH stalk) ? I'd just hate for you to start pulling things apart to find it was an easy fix
50th RR 1998 4.6L GEMS, 50th Defender 4.0L GEMS, Nanocom Evo (P38/ GEMS)
Formerly 200Tdi 90 CSW and SWB Series 3
SW London