Sony MDX-C6500RX service manual “H” tuner power on

•MAIN BOARD IC501 MB90574PMT-G-266-BND (MASTER CONTROLLER)

Pin No.	Pin Name		I/O		Description
1	TUNON		O	Tuner system power supply on/off control signal output to the BA4908 (IC671)
				“H”: tuner power on
2	ANT CUT		O	Tuner system power supply on/off control signal output terminal “H”: tuner power on
				Not used (open)
3	BUSON		O	Bus on/off control signal output to the MD mechanism controller (IC501) and SONY bus
				interface (IC701) “L”: bus on
4 to 6		NCO	O	Not used (open)
7	ILLON		O	Power on/off control signal output of the illumination LED and liquid crystal display driver
				(IC901)	“H”: power on
8		VCC	—	Power supply terminal (+5V)
9	E2P SIO		I/O	Two-way data E2P bus with the FM/AM tuner unit (TU1)
10	E2P CKO		O	E2P bus clock signal output to the FM/AM tuner unit (TU1)
11	SYSRST		O	System reset signal output to the MD mechanism controller (IC501) and SONY bus interface
				(IC701)	“L”: reset
12	DOORSW		I	Front panel open/close detection signal input terminal
				“L” is input when the front panel is closed
13	LCDSO		O	Serial data output to the liquid crystal display driver (IC901)
14	LCDCKO		O	Serial data transfer clock signal output to the liquid crystal display driver (IC901)
15	LCDCE		O	Chip enable signal output to the liquid crystal display driver (IC901)		“H” active
16		BEEP	O	Beep sound drive signal output to the power amplifier (IC611)
17		UNISI	I	Serial data input from the SONY bus interface (IC701)
18	UNISO		O	Serial data output to the SONY bus interface (IC701)
19	UNICKO		O	Serial clock signal output to the MD mechanism controller (IC501) and SONY bus interface
				(IC701)
20	UNICKI		I	Serial clock signal input from the MD mechanism controller (IC501) (for SONY bus)
21	CD MD		I	Setting terminal for the internal mechanism CD or MD
				“L”: CD, “H”: MD (fixed at “H” in this set)
22	FLASHW		I	Internal flash memory data write mode detection signal input terminal		“L”: data write mode
				Not used
23		NCO	O	Not used (open)
24	SIRCS		I	Sircs remote control signal input from the remote control receiver (IC951)
25 to 28		NCO	O	Not used (open)
29	DOORIND		O	LED drive signal output of the MD disc slot illumination and Z indicator (LED810, LSW810)
				“H”: LED on “H” is output to turn on LED when front panel is opened
30, 31		NCO	O	Not used (open)
32	NS MASK		O	Discharge control signal output for the noise detection circuit “H”: discharge
33		VSS	—	Ground terminal
34		C	—	Connected to coupling capacitor for the power supply
				A/D converter power control signal output terminal
35	AD ON		O	When the KEYACK (pin uh) that controls reference voltage power for key A/D conversion input
				is active, “L” is output from this terminal to enable the input
36	REIN0		I
				Dial pulse input of the rotary encoder (RE901)
				(for VOLUME/BASS/TREBLE/BALANCE/FADER control)
37	REIN1		I
38	DVCC		—	Power supply terminal (+5V) (for D/A converter)
39		DVSS	—	Ground terminal (for D/A converter)
40, 41		NCO	O	Not used (open)
42	AVCC		—	Power supply terminal (+5V) (for analog system)

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