Furuno SC-120 manual Parts Location, Processor unit, cover removed

				APPENDIX
Port Label	Connector	I/O	Signal	Remarks
	Type
LOG/ALARM	MJ7	O	Log	200 pulse/nm or 400 pulse/nm (software), 0.5 A max.
			signal
			HDG	Heading alarm, 0.5 A max, normal close
			alarm
HDG IN	MJ6	I	Heading	Heading data in either AD10 or IEC 61162 (NMEA
				0183) format (4800 bps) is automatically received.
				Priority of IEC 61162 (NMEA 0183) sentence is
				HDT>HDG>HDM.
				The signal is selected through the menu during the
				period of internal heading sensor failure.
				VBW/VHW/VLM may be input from a current indicator.

Note: Each GPS receiver GPS1, GPS2, and GPS3 calculates VTG/GGA/GLL/ZDA. The output from HDG OUT and NAV OUT ports is one calculated by the GPS1. However, when the GPS1 is defective, the GPS2 replaces it. When both GPS1 and GPS2 are defective, the data calculated by the GPS3 is used.

Parts Location

MAIN Board (processor) 20P8171A

PWR Board

Angular Rate 20P8164

Sensor Assy.

SC-303

Fuse

GPS Receiver

Assy. (GPS

Receiver Module)

20-513-131

(GN-77NA-NF) FIL Board 20P8165

Processor unit, cover removed

A-11