service manual (schematic) for Motorola CM540?

[capn357]

Does anyone know where I can obtain either an official Motorola service manual for the CM540 or alternatively, a good schematic for same?  I obtained an old SAMs excerpt for this unit, but the schematic is of poor quality (especially the microphone section, which is what I need).

I'm unpleasantly amazed at what appears to be the absolute dirth of information online about this radio.

(I have a microphone that won't modulate and I've been unable to diagnose or fix the problem.  No pinout information and no luck figuring anything out poking around with my multimeter (practically everything shows up as 13.6V when reverenced to the outside sleeve of the micrphone, which makes no sense to me)).

[2600]

Our database says we had the service manual 25 years ago. But where it may be is less clear. I'll make a note to look for it, but it might be after the Dayton Hamvention.

74

[capn357]

May 16, 2017 23:21:49 GMT -5 2600 said:

Our database says we had the service manual 25 years ago. But where it may be is less clear. I'll make a note to look for it, but it might be after the Dayton Hamvention.

74

Great!  Thanks.