Kenwood KRC-478R, Service Manual

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KRC-478R/RV/RY/RYV
5
CIRCUIT DESCRIPTION
(X14-) IC1 : -COM
PORT
No.
PORT NAME I/O FUNCTION OPERATING CONDITION
41 AFC O Noise detection time constant switch.
"L" : FM seeking.
"H" : The other condition.
42-44
N.C. - -
-
45 P-MUTE O Mute signal output to the power IC (IC4).
"L" : Power IC (IC4) mute.
46 SVR
O SVR signal output to the power IC (IC4).
"L" when P.ON goes down.
47 STBY O Stand-by signal output to the power IC (IC4).
"H" : Power IC (IC4) "ON".
"L" : Power IC (IC4) "OFF".
48
P-CON O Control signal output to P-CON or P-ANT.
"H" : P-CON signal output "ON".
"L" : P-CON signal output "OFF".
49 N.C. - -
-
50
BEEP O Buzzer signal output.
Beep sound output.
51
ACC-DET
I ACC detection signal input.
"H" : ACC "OFF". "L" : ACC "ON".
52
BU-DET O Back-up voltage detection signal input.
"H" when back-up signal does not exist.
"L" when back-up signal exists.
53
CH-REQ H
O Request signal output to the changer.
"L" : Request.
54
CH-CON O Changer control.
"H" : Changer mode.
"L" : The other mode.
55 N.C. - -
-
56
SW5
O SW 5V power control signal output.
"L" : SW 5V "ON".
57
P.ON O P.ON power supply control signal output.
"H" : Power "ON". "L" : Power "OFF".
58,59
- - -
-
60
RESET
I System reset signal input.
"L" : Reset. "H" : The other condition.
61
REMOTE I Data input from the remote controller.
-
62
R-CLK I Data clock input from RDS decoder .
-
63
CH-REQ C I Request input signal from the changer.
-
64
PACK IN I Insertion detection signal input from cassette mechanism.
"H" : Pack in. "L" : Pack out.
65
KEY-REQ
I Key request.
Active "L".
66
T-END I Tape-end detection signal input from cassette mechanis.
"H" : Tape running. "L" : Tape-end.
67
VSS 0 - GND.
-
68
VDD 1 - Power supply.
-
69
X2 - For main system clock oscillation.
-
70
X1 I For main system clock oscillation.
-
71
IC/TEST - For flash memory writing.
-
72
XT2 - -
-
73
VDD 0 - Power supply.
-
74
VDD 0 - Power supply.
-
75
AV REF 0 I 5V power supply (For A/D converter reference voltage).
-
76
S-METER I S-meter voltage input from the front-end.
"H" : SD signal exists.
"L" : SD signal does not exist.
Vth : Fit the new front-end.
77
T-MODE I Tape mode input from cassette mechanism.
Vth : 2.5V.
78
PHONE I Phone (Tel-mute) voltage input.
Tel mute : More than 1V.
Navi mute : Less than 2.5V.
79
NOISE I Voltage input from E-volume (IC2)’s noise amplifier.
-
80
TYPE 0 I Destination switching.
"H" : KRC-478RV/RYV.
"L" : The other models.