I have an Apollo SL60 that the com radio has failed. This unit is no longer supported by Garmin so options for repair is limited. This radio circuit board is the same as a Garmin SL-40 com radio. Does anyone have a schematic for either the SL-60 or SL-40 radio? I need to know the value of capacitor C874 (which has failed). I know this is a long shot but who knows.