Hello everyone. We purchased a 1967 M20C Nov. 1,2017, and are getting to know it. The Davtron M800M clock that is mounted in the pilot's yoke is inop. I suspect that the second "M" in the model number is for "Mooney". I took out the two mounting screws to look behind. I has no backup battery and is connected by two wires to what I assume is 14VDC. The unit displays nothing. Looking online, the M800M in the M20C is different shaped than the M800 (no second M) currently being sold. The one in my yoke has two mounting screws and a protuberance in the vertical direction to match the shape of the yoke, while the ones presently for sale are just square, and have holes for four mounting screws. Does anyone here know who might fix this or have one for sale? I want to start doing IFR training in this beast, but need a functioning clock. Thanks. I look forward to receiving some guidance.