MDX-C7890R - Sony Car Audio Service Manual (repair manual). Page 31

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50

D-BASS IN

I

D-BASS switch (LSW805) input terminal (A/D input)

51

NC

I

Not used (fixed at “L”)

52

MPDH (MTP)

I

Multi-path input from the RDS decoder (IC102)

53

S METER (VSM)

I

FM and AM (MW/LW) signal meter voltage detection input from the FM/AM tuner unit (TU1)

54

VCC

—

Power supply terminal (+5V)

55

AMP ATT

O

Muting control signal output to the power amplifier (IC500)    “H”: muting on

56

AMP ON

O

Standby control signal output to the power amplifier (IC500)    “L”: standby, “H”: amp on

57

ILL IN

I

Illuminate line detect signal input for the auto dimmer control    Dimmer is present at input of “L”

58

LOCK IN

I

Mini-disc lock detection signal input from the MD mechanism controller (IC501)    “H”: lock

59

EMPH ON

O

Emphasis control signal output to the D/A converter (IC202)    “H”: emphasis on

60

AU ATT

O

Audio line muting on/off control signal output terminal    “H”: muting on

61

AF ATT

O

RDS AF playing attenuate signal output terminal    Not used (open)

62

TU ATT

O

Tuner signal (FM and AM) muting on/off control signal output    “H”: muting on

63

VSS

—

Ground terminal

64

ACC IN

I

Accessory detect signal input terminal    “L”: accessory on

65

AF SEEK

O

RDS AF seek control signal output terminal

66

NC

O

Not used (open)

67

DAVN

I

Data transmit completed detect signal input from the RDS decoder (IC102)

68, 69

NC

O

Not used (open)

70

RDS SI

I

Serial data input from the RDS decoder (IC102)

71

RDS CKI

I

Serial data transfer clock signal input from the RDS decoder (IC102)

72

RC IN1

I

Rotary remote commander shift key A/D input terminal

73

X1A

O

Sub system clock output terminal (32 kHz)

74

X0A

I

Sub system clock input terminal (32 kHz)

75

NC

O

Not used (open)

76

BU IN

I

Battery detect signal input from the SONY bus interface (IC600) and battery check circuit
“H”: battery on

77, 78

NC

O

Not used (open)

79

KEYACK

I

Input of acknowledge signal for the key entry    Acknowledge signal is input to accept function
and eject keys in the power off status    On at input of “H”

80

TEL ATT

I

Telephone muting signal input terminal    At input of “L”, the signal is attenuated by –20 dB

81

ST IN/MONO

I/O

82

SEEKOUT

O

Seek control signal output to the FM/AM tuner unit (TU1) (AM mode: used for IF count output,
SD request, AGC cut etc., FM mode: used for SEEK, BTM, AF playing SD speed up etc.)

83

SD IN

I

Station detector detect input from the FM/AM tuner unit (TU1)
Stop level for SEEK, BTM, etc. is determined    SD is present at input of “H”

84

NC (MONO)

I

Not used (open)

85

PLL CE

O

PLL serial chip enable output to the FM/AM PLL (IC100)

86

HSTX

I

Hardware standby input terminal    Not used (open)

87

MD2

I

Mode selection input terminal (fixed at “L”)

88

MD1

I

Mode selection input terminal (fixed at “H”)

89

MD0

I

Mode selection input terminal (fixed at “H”)

90

RESET

I

System reset signal input from the reset signal generator (IC801) and reset switch (S900)
“L” is input for several 100 msec after power on, then it changes to “H”

91

VSS

—

Ground terminal

Input of FM stereo detection signal from FM/AM tuner unit (TU1), and output of forced
monaural control signal to FM/AM tuner unit (TU1)  (Commonly used for stereo display input
and forced monaural output)
FM stereo detection at input of “L”, forced monaural at output of “L”