Kenwood KDC-237SA User manual

© 2006-12 PRINTED IN JAPAN
B53-0481-00 (N)345
CD RECEIVER
KDC-237SA/237SAY
KDC-237SG/237SGY
SERVICE MANUAL
This product uses Lead Free solder.
KDC-237
SCAN RDM REP
DISP
/ PTY
VOL
ATT
AUD
SET UP
TI AME
MENU
B.BOOST
AM
FM
SCRL
Antenna adaptor
(T90-0523-05)
SPARE TDF PANEL
MAIN UNIT NAME TDF PARTS No. TDF NAME
KDC-237SA/237SAY Y33-2660-62 TDF-237A
KDC-237SG/237SGY Y33-2660-63 TDF-237G
DC cord
(E30-6427-05)
Lever
(D10-4589-04) x2
Escutcheon
(B07-3122-01)
Panel assy
KDC-237SA/237SAY/237SG/237SGY (A64-4059-02)
Mounting hardware assy
(J21-9716-03)
Carrying case
(W01-1685-05)

2
KDC-237SA/237SAY
KDC-237SG/237SGY
BLOCK DIAGRAM
2
16
1
FRONT/
P.ON FL
BU DET
PHONE
ACC DET
RST
PHONE
ACC DET / BU DET
PS1-1 / PS1-2 / PS1-3
P.ON FL
PS2-1 / PS2-2
9
5
9
BU DET
11
3
MUTE
8
R11-15
12
3
3
3
1
ROM CORRECTION (NOT USED)
1
1
REAR/SW
111
1
R80-82
P-ANT
P-CON
B.U.
ACC
PHONE
SP-OUT
PS2-1 / PS2-2
PS1-1 / PS1-2 / PS1-3
R103
1
FL+B
2
LX-BUS
E-VOL
IC2 or IC3
A8V
SYSTEM u-COM
BU
POWER
DC-DET
Q701-704 PRE-OUT
PHONE
ACC-DET
Q101
SURGE-
Q103
BU-DET
Q102
SW14V
Q1
Q2
DC-CN
A8V
SERVO+B
D5
BU5
SW5
DET
BU
DC-CN etc
BU5
PAN5V
WIRED
REMOTE
RESET IC
IC8
ILLUMI+B
CN
RESET ENCODER
ROTARY
REMOTE
ILLUMI
KEY
MATRIX
KEY
VFD
IC1
SW5
IC6
IC2
J1
+B
ILLUMI
ILLUMI+B
AM+B
S1
ED1
CN4,J5
MUTE
Q705
J4
J2
A1
SERVO+B
A8V
Q302
BU5
1/2W
Rx5
Q301
BU5
BU5
Q901-903
DME1
BU5
SW5
CD
SERVO
SW5
IC
CN3
to GND
S3
J1
SW5
AM+B
A8V
TUNER
FRONT-END
ANT.
DECODER
RDS
IC7 SW5
ANALOG
SW
IC9
E2PROMSW5
BU MECHA
CD
CONT
SW
Q401
A8V A8V
PRE-OUT
MUTE
BU5
SW5
DSI
F-AUX
J2
PANEL DET Rx3
1/2W
IC1
BU5
SW5
SW14V
FL+B
IC4
POWER
SUPPLY
IC
FL+B
J3
BU5
IC10
VFD
DRIVER
Q8,9
Q7
ELECTRIC UNIT (X34- )
SWITCH UNIT (X16- )
DPU1
CD PLAYER UNIT (X32-598x-xx) BOARD (X34- )
MOTHER
EF
ACB
TR COIL
FO COIL
APC
IC1
16.93MHz
CLOCK
IC6
8V SW
3.3V REG
IC3
LOADING &
RF AMP
SERVO
PROCESSOR
MOTOR
DRIVER
MOTOR
SPINDLE
3.3V REG
IC2
S2
S4
S1
S3
+
+
ONLY
SLED
MOTOR
DM1
DM2
Q1
X2
Q7
PROCESSOR
MICRO
1 CHIP IC
LEVEL SHIFT
LEVEL SHIFT
LEVEL SHIFT
Q3
Q3
Q4
(0-00),(0-01) ONLY
SW
Q2
SW
Q8,9
3.3V SW
Q6
SW (0-01),(0-03)
ONLY
(0-00),(0-01)
X1 or
VREF
D.GND
BU5V
8EJE-SW
12EJE-SW
LOS-SW
LOE/LIM-SW
D.GND
MOTOR
LO/EJ
S.GND
D.GND
D.GND
S.GND
A.GND
AS8V
R-ch
L-ch
S.GND
DMUTE
A,B,C,E,F
VREF
TR OUT
FO OUT
DM OUT
FM OUT
TVD,SPL
FOD,TRD,
DATA
CLK
MSTOP
RST
MUTE
MUTE
CLK
DATA
MSTOP
MRST
D.GND
S7V
AVDD
REGVDD
P-ON1
IOVDD

3
KDC-237SA/237SAY
KDC-237SG/237SGY
●ELECTRIC UNIT (X34-4672-78)
Ref. No. Application / Function Operation / Condition / Compatibility
IC1 System µ-COM Controls FM/AM tuner, the changer, CD mechanism, panel, volume and tone.
IC3 E-VOL Controls the source, volume and tone.
IC4 Power Supply IC Outputs 5Vx2, 8.1Vx2, 10.2V, P-CON and P-ANT.
IC6 Power IC Amplifies the front L/R and the rear L/R to 45W maximum.
IC7 RDS IC RDS decoder.
IC8 Reset IC Lo when detection voltage goes below 3.6V.
Q1 SW14V ON when the base goes Hi.
Q2 Servo+B AVR When Q3’s base goes Hi, Servo+B AVR outputs 7.5V.
Q3 Control SW for Servo+B ON when the base goes Hi.
Q7 VFD+B SW ON when the base goes Hi.
Q8 VFD+B AVR When Q9’s base goes Hi, Servo+B AVR outputs 10.5V.
Q9 Control SW forVFD+B ON when the base goes Hi.
Q101 ACC DET ON when the base goes Hi during ACC is applied.
Q102 Serge DET When the base goes Hi, surge voltage is detected.
Q103 BU DET ON when the base goes Hi during BU is applied.
Q104,105 Mute Control ON when the base goes Hi.
Q301 Panel 5V SW ON when the base goes Lo.
Q302 DSI ILLUMI SW ON when the base goes Hi.
Q901 DC Offset DET ON when the base goes Hi after Q902’s and Q903’s outputs are separated.
Q902,903 DC Offset DET SW ON when the bases go Lo after IC6’s SP-OUTs (DC) are separated.
●SWITCH UNIT (X16-386x-xx)
Ref. No. Application / Function Operation / Condition / Compatibility
IC1 VFD Driver
●CD PLAYER UNIT (X32-5980-00)
Ref. No. Application / Function Operation / Condition / Compatibility
Focusing, tracking, sled and spindle servo processing.
Automatic adjustment (focusing, tracking, gain, offset and balance) operations.
CD Signal Processor Digital signal processing (DSP, PLL, sub-codes, CIRC error correction, audio data
IC1 & MECHA µ-COM interpolation processing) operations, and microcomputer function.
RF Amplifier responding Generation of RF signal based on the signals from the APC circuit and the laser pick-up,
to CD-RW and generation of servo error (focusing error and tracking error) signals.
Detection of dropout, anti-shock, track crossing and off-tracking conditions, included gain
control function during CD-RW.
IC2 3.3V REG Supplies 3.3V to IC1 and the laser pick-up.
IC3 3.3V REG Supplies 3.3V to IC1 and audio circuit.
IC6 4ch BTL Driver Focusing and tracking coil, sled and spindle motor driver, disc loading and eject operation.
Q1 A8V SW Q1 is ON when Q2 is ON.
COMPONENTS DESCRIPTION

4
KDC-237SA/237SAY
KDC-237SG/237SGY
Ref. No. Application / Function Operation / Condition / Compatibility
Q2 Q1 SW Q2 is ON when Q6 is ON.
Q3 5V-3.3V Level Shift Shifts 5V to 3.3V, or 3.3V to 5V.
Q4 5V-3.3V Level Shift Shifts 3.3V to 5V.
Q6 BU3.3V SW Q6 is ON when Q8 or Q9 is ON.
Q7 APC (Auto Power Control) Drives LD (Laser Diode).
Q8 Power Supply Control Power Supply Control from MECHA µ-COM.Q6 is ON when pin 63 (P_ON1) of IC1 is Hi.
Q9 Power Supply Control Power Supply Control from system µ-COM.Q6 is ON when pin 125 (MSTOP) of IC1 is Hi.
D1,2 5V ForceVoltage Prevention 5V ForceVoltage Prevention from MECHA µ-COM side.
D3 Laser Diode Protection Prevents reverse bias which is applied to laser. Laser destruction prevention.
D4 Static Electricity Countermeasure Prevents malfunction by static electricity.
●SYSTEM µ-COM: IC1 on X34- (ELECTRIC UNIT)
Pin No. Pin Name I/O Application
Truth Value
Processing Operation Description
Table
1LX DATA M I/O Data to slave unit Pull-down (GND)
2LX CLK I/O LX-BUS clock 125k~65kHz
3~5 NC - Not used Output Lo fixed
6 REMO I Remote control signal input Detects pulse width
7NC-Not used Output L fixed
8 BYTE I Memory extended bus width setting Connects to VSS
9CNVSS - Connects to VSS
10 XCIN - 32.768kHz
11 XCOUT - 32.768kHz
12 RESET - L: Reset
13 XOUT - 10.0MHz
14 VSS -
15 XIN - 10.0MHz
16 VCC1 -
17 NMI I Connects to VSS
18 PANEL DET I Panel communication detection H: Panel detached, L: Panel attached
19,20 NC - Not used Output L fixed
21 ROMCOR DET IE2PROM writing request H:Writing
22,23 NC - Not used Output L fixed
MICROCOMPUTER’STERMINAL DESCRIPTION
COMPONENTS DESCRIPTION

5
KDC-237SA/237SAY
KDC-237SG/237SGY
Pin No. Pin Name I/O Application
Truth Value
Processing Operation Description
Table
24 PON FL O Key illumination power supply control ON: H, OFF: L
25 NC - Not used
26 PON PANEL I/O Panel 5V control ON: L, Momentary power down/Panel detached
: Hi-Z, 11 minutes after ACC OFF: Hi-Z
27 NC - Not used Output L fixed
28 PWIC BEEP O Beep output
29 AUD SCL I/O E-VOL clock output
30 AUD SDA I/O E-VOL data input/output
31 VFD SYS DATA OVFD data output
32 VFD PAN DATA I VFD data input
33 VFD CLK O VFD clock output 125kHz
34 VFD BLK O VFD data blanking output
H: Reset cancelled, L: Reset, Momentary power down
/Panel detached: L, 11 minutes after ACC OFF: L
35 CD SI O CD mechanism serial output
36 CD SO I CD mechanism serial input
37 CD CLK O Serial clock output 1MHz
38 CD LOS SW I CD loading detection
39 PIO0 I Communication request from mechanism DSP H: Data request
40 CD SRAMSTB O 1M-bit SRAM standby H: SRAM standby
41 EPM I Flash EPM input Connects to VSS
42 CD LOE LIM SW ICD detection (Chucking SW) H: Loading completed, L: No disc
43 PON CD O CD mechanism power supply control H:Power ON
44 CD LOEJ I/O CD motor control qRefer to the truth value table
45 CD MOTOR I/O CD motor control qRefer to the truth value table
46 VFD CE O VFD control request
47 CD DRIVEMUTE OMotor driver mute output
48 CD CCE O CD mechanism chip enable
49 CD DISC8 SW I 8cm disc detection Pull-up (B.U.)
50 CD MRST O CD mechanism µ-com reset H: Normal, L:Reset
51~53 NC - Not used Output L fixed
54 CD MUTE I CD mute request L: Mute request
55 CD DISC12 SW I 12cm disc detection Pull-up (B.U.)
56 ROTARY CCW I VOL key input Detects pulse width
57 ROTARY CW I VOL key input Detects pulse width
58 NC - Not used Output L fixed
59 DSI I/O DSI control OFF: Hi-z, Panel detached:Pulse drives, ON: H
60 RDS DATA I RDS decoder data input
61 RDS QUAL I RDS decoder QUAL input
62 VCC2 -
MICROCOMPUTER’STERMINAL DESCRIPTION

6
KDC-237SA/237SAY
KDC-237SG/237SGY
Pin No. Pin Name I/O Application
Truth Value
Processing Operation Description
Table
63 NC - Not used Output L fixed
64 VSS -
65 RDS AFS M I/O Noise detection time constant switching wRefer to the truth value table
66 TUN IFC OUT I Front-end IFC-OUT input H: Station found, L:No station
67 PON EXT GND I/O IC2 external input quick charge control
L: OFF, Hi-Z: Quick charge, When IC2 is in source select:
Hi-Z, Mute L: L, Momentary power down/Power OFF: L
68 MUTE I/O Mute L: Mute OFF, Hi-Z: Mute ON
69 ANALOG CON OAUX/LX audio switching AUX: H (Switches after 100ms after first-out mute
begins to work), LX/Other source: L
70 LX RST O Forced reset to slave unit H: Reset, L: Normal
71 LX CON O Start-up request to slave unit H: Slave unit ON, L:Slave unit OFF
72 LX MUTE I Mute request from slave unit H: Mute ON, L: Mute OFF
73 LX REQ M O Communication request to slave unit
74 RDS CLK I RDS decoder clock input
75 LX REQ S I Communication request from slave unit Pull-down (GND)
76 PWIC SVR O SVR discharging circuit During 500ms after momentary power down: H,
Since then: L
77 PWIC STBY O Power IC standby control Power ON: H, Power OFF: L
78 PWIC MUTE O Power IC mute STANDBY source/Momentary power down: L,
TEL mute: L
79 ACC DET I ACC power supply detection ACC found: L, No ACC: H
BU found: L, No BU/Momentary power down: H
80 BU DET I Detection of momentary power down (Operates after less than 4ms after momentary
power down is detected)
81,82 NC O Not used Output L fixed
83 RDS NOISE I FM noise detection
84 TUN SMETER I S-meter input
85 TYPE1 I Destination switching eRefer to the truth value table
86 TYPE2 I Destination switching eRefer to the truth value table
87 PWIC DC DET IDC offset detection
If DC offset is found 20 times in 100ms with condition
of over 1.0V, it will be judged as DC offset detected.
88 LINE MUTE I Line mute selection TEL mute: Below 1V, NAVI mue: Over 2.5V
89 OFFSET DET I Power IC offset detection
90 PS2 2 O Power supply IC control rRefer to the truth value table
91 PS2 1 O Power supply IC control rRefer to the truth value table
92 PS1 1 O Power supply IC control rRefer to the truth value table
93 PS1 2 O Power supply IC control rRefer to the truth value table
94 PS1 3 O Power supply IC control rRefer to the truth value table
95 PON - Not used POWER ON: H, POWER OFF: L
MICROCOMPUTER’STERMINAL DESCRIPTION

7
KDC-237SA/237SAY
KDC-237SG/237SGY
•Truth value table
qCD motor control
CD motor CD loading/eject
Stop L L
Load H L
Eject H H
Brake H Hi-z
wAFS control
RDS AFS M Condition
AFS MID L Except AF search, seeking or tuner source
AFS HIGH Hi-Z Normal reception
eDestination switching
TYPE 2 TYPE 1 Model
(Pin 86) (Pin 85)
2.4V 0V KDC-237SA/237SAY/237SG/237SGY
rPower supply IC (IC4) control
SEL1 (Pin 10)
PS1-2 PS1-3 PS2-1 ILLUMI P-CON P-ANT
LLLOFFOFF OFF
LLHONOFF OFF
HLHONONOFF
HHHONONON
SEL2 (Pin 11)
PS1-1 PS2-2 AUDIO/SW5 AM
LLOFF OFF
HLONOFF
HHONON
Pin No. Pin Name I/O Application
Truth Value
Processing Operation Description
Table
96 AVSS -
97 REF CON O VREF control Connects to VREF
98 VREF -
99 AVCC -
100 LX DATA S I Data from slave unit Pull-down (GND)
MICROCOMPUTER’STERMINAL DESCRIPTION

8
KDC-237SA/237SAY
KDC-237SG/237SGY
■Example
Key Description of display Description
5Disc EJECT times display
E J C X X X X X
Disc EJECT times display. MAX 65535 (times)
■5While disc EJECT times is displayed, press and hold for
2 seconds or longer to clear disc EJECT times.
A symbol “■” in the key column indicates that the key should be pressed and held for 1 second or longer.
■How to enter the test mode
Procedure Note
Press and hold the [1] key and [3] key and reset.
All lamps blink when it is detected that the sub-clock resonator is disconnected.
Do not display “CODE_OFF”, “CODE_ON”or “CODE_NG” when Power is ON.
When having started up in the test mode, change the LINE MUTE inhibition time from 10 seconds to 1 second.
When operating in the test mode, even if a DC offset error occurs, detection information is not written in the E2PROM.
When operating in the test mode, CD mechanism error log information clear mode, and DC offset error detection information clear mode, do not
perform DEMO mode operations.
Also, do not display DEMO ON/OFF option items in the MENU in STANDBY source in the above modes.
Forced disc ejection is prohibited in the test mode.
■How to clear the test mode
Procedure Note
Reset, momentary power down, ACC OFF, Power OFF, Panel detached. Clearing the test mode
■Test mode default condition
Description Default values
Source STANDBY
Display Display lights are all turned on.
Volume -10dB (“30”is displayed.)
Bass Boost OFF
CRSC OFF regardless of having/not having the switching function.
AUX ON
System Q NATURAL (FLAT)
Beep Sound on with a key pressed regardless of any settings.
Preout Sub Woofer
::.
TEST MODE

9
KDC-237SA/237SAY
KDC-237SG/237SGY
■Special displays when all lights are on in STANDBY source
Key Description of display Description
Common All lights ON. All lights ON.
1Destination terminal
T Y P E :1 1
“TYPE” indicates system µ-com (IC1) destination, and shows
condition indication real-time condition of the destination terminal.
Development ID condition
6 1 1 A 2 – 3 .0 0
Development ID – Version (system µ-com: IC1)
indication
2Serial No.display
00000000
Serial No.is displayed (8 digits)
3Power ON time display
P O N 0 H X X
00~50 is displayed for “XX”. When less than 1 hour,
displayed by displayed by increments of 10 minutes.
P O N X X X X X
00001~10922 is displayed for “XXXXX”. MAX 10922 (hours)
■3When Power ON time is displayed, press and hold for
2 seconds or longer to clear Power ON time.
4 Disc operation time display
C D T 0 H X X
00~50 is displayed for “XX”. When less than 1 hour,
displayed by increments of 10 minutes.
C D T X X X X X
00001~10922 is displayed for “XXXXX”. MAX 10922 (hours)
■4While the disc operation time is displayed, press and hold for
2 seconds or longer to clear the disc operation time.
(Cleared only for displayed media.)
5Disc EJECT times display
E J C X X X X X
Disc EJECT times display. MAX 65535 (times)
■5While disc EJECT times is displayed, press and hold for
2 seconds or longer to clear disc EJECT times.
6Panel open/close
P C X X X X X
PANEL open/close times display. MAX 65535 (times)
■6times display Press the key for more than 2 seconds while the PANEL open/
close count is displayed and PANEL open/close count is cleared.
FM ROM correction version
R O 1 2 3
The number is the ROM correction version number.
display
E R R
When E2PROM is not installed.
R – – – –
When not written in yet.
****
R
When data not matched. (due to the difference in versions)
■AM ROM data transfer
Audio data initialization
A N I TUD I
AUDIO setting value is re-set to the test mode default value.
Forced Power OFF
P – – –OFF
No forced power OFF
information display
P S E COFF
Forced power OFF because of missing Security Code.
(Code security supporting model)
P P N LOFF
Forced power OFF by communication error between system
µ-com and panel.
■While the forced power OFF data is displayed, press and
hold for 2 seconds to clear the data.
CD information display For the display contents, refer to “CD information display
mode ON/OFF mode” in the next section.
■While in CD information display mode, press and hold for
2 seconds or longer to clear all CD information.
TEST MODE

10
KDC-237SA/237SAY
KDC-237SG/237SGY
• CD information display mode
Key Description of display Description
FM I2C com-
I K2C O
I2C communication OK
(forward munication
rotation) status
I G2C N
I2C communication NG
AM
(reverse / CD mecha-
M 1 :X XCERR
Mechanism error log 1 (Latest)
rotation) nism error XX: Error number. “– –” is displayed in case there is no error.
log display
M 2 :X XCERR
Mechanism error log 2 (Latest)
XX: Error number. “– –” is displayed in case there is no error.
M 3 :X XCERR
Mechanism error log 3 (Latest)
XX: Error number. “– –” is displayed in case there is no error.
/ CD Load
L 1 :X XDERR
Load error switch 1
error XX: Number of errors. “– –” is displayed in case there is no error.
information
L 2 :X XDERR
Load error switch 2
display XX: Number of errors. “– –” is displayed in case there is no error.
/ CD Ejection
E 1 :X XJERR
Ejection error switch 1
error XX: Number of errors. “– –” is displayed in case there is no error.
information
E 2 :X XJERR
Ejection error switch 2
display XX: Number of errors. “– –” is displayed in case there is no error.
E 3 :X XJERR
Ejection error switch 3
XX: Number of errors. “– –” is displayed in case there is no error.
E 4 :X XJERR
Ejection error switch 4
XX: Number of errors. “– –” is displayed in case there is no error.
/ CD time code
C O S ENT L
CD time code error count data (Missing counts) mode display.
error count
C X:XDDA
Number of CD-DA count errors
data display XX: Number of errors. “– –” is displayed in case there is no error.
(Missing
counts)
/ CD time code
C T A YNT S
CD time code error count data (count not updated) mode display.
error count
C X:XDDA
Number of CD-DA count errors
data display XX: Number of errors. “– –” is displayed in case there is no error.
(count not
updated)
TEST MODE

11
KDC-237SA/237SAY
KDC-237SG/237SGY
■Test mode specifications inTUNER source
Error is found in front-end (A1), etc.if indications below is displayed while in tuner source.
Status Display Description
Front-end (A1) E2PROM data error
T N GNE2P
Front-end (A1) E2PROM is still the default (unspecified) value.
Front-end (A1) communication error
T N GNCON
Communication with front-end (A1) is not possible.
•TUNER preset operation
Key Description of display Description
4 Preset function
F 8 .3 A 4M1 9
Change to 98.3MHz with the preset key [4].
• K3I forced switching
Every time when [6] key is pressed in tuner FM source, switched in the following order: AUTO →Forced WIDE →Forced MIDDLE →Forced
NARROW →AUTO.Default status is AUTO, and displayed as shown below.
Key Description of display Description
6K3I Forced switching
F 8 .1 AM1 9
AUTO
F 8 .1 WM1 9
Forced WIDE
F 8 .1 MM1 9
Forced MIDDLE
F 8 .1 NM1 9
Forced NARROW
• RDS auto measurement
Add the process to replace the visual inspection of PS display previously done in the production line.
Status Display Description
PS data reception
R E S TDS T
If displayed as shown at the left, force to OFF.
P-CON is recovered by Power OFF/ON.
• FST adjustment mode
Perform FST soft-mute adjustment.
Key Note
■Enter the FST adjustment mode.(Press for 1 second or longer.)
Operations in the FST adjustment mode are as follows:
Key Description of display Description
FM (UP) Soft-mute adjustment
SMD–F
18dBµ(0) ↔36dBµ(F)
AM (DOWN)
■Adjustment value
E I T EPWR
Displays the data that has been written in the E2PROM when
memory pressing the key for 2 seconds or longer.
Mode clear
F 8 .3 A 4M1 9
Clear the FST adjustment mode.(Returns to normal display
and the test mode is retained.)
After completing the FST adjustment, ifYou wish to clear the test mode,You can do this using the reset button.
TEST MODE

12
KDC-237SA/237SAY
KDC-237SG/237SGY
■Test mode specifications in CD source
Display mode default: P-Time
• Procedure in CD-DA media (KTD-02A)
Key Description of display Description
Track up procedure Every time pressed, jumps to the track shown below.
No.9 →No.15 →No.10 →No.11 →No.12 →No.13 →
No.22 →No.14 →No.9 (recursive)
But in case the disc has 8 tracks or less, playback starts with
track No.1.
Track down procedure Goes down by 1 track from the currently played track.
1Jump procedure Jump to No. 28 (Scratch 0.7mm for MUSIC line vibration testing)
2Jump procedure Jump to No. 14 (Blurring surface disc TCD-731RA Tr14)
3Information display
6E00:
Display of Mechanism model name and Mechanism version.
Mechanism model name (When key is pressed while the display in the left is being
Mechanism version shown, returns to normal display.)
6Jump procedure Jump to No. 15. Set the volume value to “25”.
(For 20Hz 0dB DC protection false-operation FCT checking)
Used media: For CD, KTD-02A
■Audio-related test mode
Procedure Note
Press the [AUD] key (main unit) Enter audio adjustment mode (the initial item should be Fader, and then, Balance →
Press the [AUD] and [∗] keys (Remote control) Bass Level →Middle Level →Treble Level →System Q →V-Offset →
About audio adjustment items (include both Audio Function Mode and Audio Setup Mode)
Procedure Item Procedure Description
For item Fader [VOL] knob and [ / ] key Adjust to 3 steps of R15 ↔0 ↔F15. (Default value: 0)
forwarding Balance [VOL] knob and [ / ] key Adjust to 3 steps of L15 ↔0 ↔R15. (Default value:0)
procedure, Bass Level [VOL] knob and [ / ] key Adjust to 3 steps of -8 ↔0 ↔+8. (Default value 0)
press [AUD] Middle Level [VOL] knob and [ / ] key Adjust to 3 steps of -8 ↔0 ↔+8. (Default value 0)
key and Treble Level [VOL] knob and [ / ] key Adjust to 3 steps of -8 ↔0 ↔+8. (Default value 0)
[FM] key LPF Sub woofer [VOL] knob and [ / ] key Adjust to 2 steps of 80Hz ↔Through. (Default value:Through)
(Only in models with Sub Woofer output)
Volume Offset [VOL] knob and [ / ] key Adjust to 3 steps of -8 ↔0 ↔+8.(Default value 0)
Procedure Note
Press the [B.BOOST] key for 1 second or longer Switch Bass Boost (Note: Front key functions as MENU.)
TEST MODE

13
KDC-237SA/237SAY
KDC-237SG/237SGY
■MENU-related test mode
Procedure Note
Press the [B.BOOST] key (main unit) Continuous forwarding by remote control is prohibited
Press the [DNPP/SBF] and [DIRECT] keys (Remote control)
■Backup current measurement
Procedure Note
While ACC OFF (Back Up ON), Reset MUTE terminal is OFF after 2 seconds, not after 15 seconds.
(During this time, the CD mechanism does not function.)
■Fluorescent indicator tube (ED1) short check
Procedure Note
In the STANDBY source, press [ATT] key All lights are off →Turns on odd and even terminals alternatively every
125ms (terminals that have a maximum number of grids) →Turns on only
the odd terminals →Turn on only the even terminals →
■ Clearing CD mechanism information / Service information / DC offset error information (Clearing E2PROM data)
Status Display Description
While pressing and holding [B.BOOST]
CDO
At normal termination
key and [ATT] key, reset-start.
CDX
At abnormal termination
While “– – – –” is displayed, power can be ON for 30 minutes.This mode is cancelled by resetting.(The last screen will not be retained.)
Data to be cleared is shown below.
CD mechanism information I2C communication status display
CD mechanism error log display
Displays CD loading error data
Displays CD EJECT error data
Displays CD time code count error data (missing count)
Displays CD time code count error data (count not updated)
Service Information Power ON time display
CD operation time display
CD EJECT times display
PANEL open/close times display
Forced Power OFF information display
DC offset error information DC offset error 1 display (Provides information on whether there is an improper connection or another error)
DC offset error 2 display (Provides information on the number of capacitor leaks)
■Clearing DC offset error detection data (E2PROM data clearing)
Procedure Note
While pressing and holding [3] key and [6] key, reset-start. Entering DC offset error display mode.
TEST MODE

14
KDC-237SA/237SAY
KDC-237SG/237SGY
Procedure Display Description
Press and hold the [3] and
D R RCE
When DC offset error is detected (when either one of capacitors is
[6] keys, and reset-start leaking, or an improper connection or another error is detected)
D KCO
When DC offset error is not detected (when none of capacitors leak,
no improper connection or other error is detected)
1
D R RC1 E
When improper connection or other DC offset errors are detected.
D KC1 O
When improper connection or other DC offset errors are not detected.
■1
D KC1 O
When detecting improper connection or other DC offset errors, clears
detection data. (Clear E2PROM)
2
DC2 4
When detecting capacitor leak, provides information on the number
of capacitor leaks.(0~4)
■2
DC2 0
When detecting capacitor leak, clears the number of capacitor leaks.
(Clear E2PROM)
This mode is cancelled by resetting.(The last screen will not be retained.)
■ROM data transfer
When replacing front-end (A1), this function is used to transfer E2PROM data (ROM correction, security and other data) to front-end (A1) to
E2PROM of to mother unit (X34-), used for saving data, and, after completing replacement of front-end (A1), to recover data from the E2PROM of
the mother unit (X34-), and for saving data to the new front-end (A1).Refer to“ROM data transfer processes” on the next page for details on front-
end (A1) replacement procedures and on the data to be transferred.
Procedure Display Description
While pressing and holding
:
All lights ON.
[1] key and [3] keys, reset-start
Press [B.BOOST] key (MENU)
R E A DOM R
MENU mode
Press [ ] key or [ ] key
R E A DOM R
Front-end (A1) →Mother unit (X34-). Data transfer processing.
R R TOM W
Mother unit (X34-) →Front-end (A1).Data transfer processing.
(In the above ROM READ
READ
Front-end (A1) →Mother unit (X34-). ROM data is being transferred.
status), ■[] key for
R O KEAD
Front-end (A1) →Mother unit (X34-).
2 seconds or longer ROM correction transfer, security and other data is OK.
R O K 2EAD
Front-end (A1) →Mother unit (X34-).
Transfer of security and other data is OK.
R N GEAD
Front-end (A1) →Mother unit (X34-). ROM data transfer is NG.
(In the above ROM WRT
WRT
Mother unit (X34-) →Front -end (A1).ROM data is being transferred.
status), ■[] key for
W O KRT
Mother unit (X34-) →Front-end (A1).
2 seconds or longer ROM correction, security and other data transfer is OK.
W O K 1RT
Mother unit (X34-) →Front-end (A1).
ROM correction data transfer is OK.
W O K 2RT
Mother unit (X34-) →Front-end (A1).
Transfer of security and other data is OK.
W N GRT
Mother unit (X34-) →Front-end (A1).ROM data transfer is NG
(In every status of ROM data
:
Clear from ROM correction data transfer processing
[] transfer processing)
TEST MODE

15
KDC-237SA/237SAY
KDC-237SG/237SGY
When replacing front-end (A1) of mother unit (X34-), or when
adding or replacing ROM correction (program correction with
ROM IC (IC10)), the following activities are required.
■Overview
When replacing front-end (A1) in the model where ROM cor-
rection and security data have been written into E2PROM,
included in the front-end (A1) pack, the transfer function of the
E2PROM data itself in the replaced front-end (A1) is required.
This function in the above system configuration is used to al-
low for complete replacement of the front-end at any service
center.
■Overview of specifications
Procedures for replacement are as follows: To install the
E2PROM to the mother unit (X34-), and replace front-end (A1)
with new front-end after copying the data in the E2PROM (such
as ROM correction data and other data) in the front-end (A1)
to the mother unit (X34-) by operating the system, and then
copy the data (such as ROM correction data and other data)
into the mother unit to the E2PROM of the front-end (A1), op-
erating the main body.
Tuner adjustment data was inserted during the tuner pack
manufacturing, and data will not be transferred because front-
end (A1) is built-in.
In addition, tuner adjustment data for new front-end (A1) is
supplied as a service part in which data was inserted.
■Data to be copied
• ROM correction data
• Other data
Security data
DEMO MODE ON/OFF status
POWER ON time (For maintenance)
Playback time (For maintenance)
EJECT count (For maintenance)
Panel open/close count (For maintenance)
CD I2C status (For maintenance)
CD offset error code (For maintenance)
CD sound skips count (For maintenance)
CD time code not updated count (For maintenance)
CD load switch errors count (For maintenance)
CD ejection errors count (For maintenance)
DC offset error (For maintenance)
Forced Power OFF information (For maintenance)
Serial number (For maintenance)
E2PROM data check data (For internal check)
ROM DATATRANSFER PROCESSES
■Operation procedure
Operation procedure is different depending on the conditions.
Proceed with the appropriate operation procedure depending
on the specific condition.
1. In case of replacing front-end (A1) without an applicable
ROM correction.
2. In case of replacing front-end (A1) with an applicable ROM
correction.
3. In case of applying new ROM correction at the same time
when front-end (A1) is replaced. (No ROM correction has
been carried out.)
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
E2PROM circuit pattern
q
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
w
Install new E2PROM.
Install E2PROM containing no data, in case of [1] and [2].
In case of [3], install maintenance E2PROM with an applicable
ROM correction program.

16
KDC-237SA/237SAY
KDC-237SG/237SGY
Turn power on.
Press and hold the [1] and [3] keys and press reset button.
(Enter the system in the test mode.)
Press [B.BOOST] key. (ROM data System enters data trans-
fer mode.)
Press [ ] (or [ ].) (Select READ)
Press [ ] key for 1 second or longer.(Data transfer)
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
e
The system µ-COM (IC1) copies
the data in the front-end (A1) in the
E2PROM on the mother unit (X34-)
READ OK
In case of [2]
In case of [1] or [3]
R-OK
READ OK2 R-O2
FRONT-
END (A1)
E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
r
Press [ ] key. (Exit ROM data transfer mode.)
Turn power off.
Remove front-end (A1).
Install new front-end (A1).
No ROM correction or other data status.
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
t
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
y
System µ-COM (IC1) copies
data on the mother unit (X34-) into
E2PROM in the front-end (A1)
WRT OK
In case of [2] or [3]
In case of [1]
W-OK
WRT OK2 W-O2
Turn power on.
Press and hold the [1] and [3] keys and press reset button.
(Enter the system in the test mode.)
Press [B.BOOST] key. (Start transferring ROM data.)
Press [ ] (or [ ].) (Select WRT)
Press [ ] key for 1 second or longer. (Data transfer)
Press [ ] key. (Exit ROM data transfer mode.)
ROM DATATRANSFER PROCESSES

17
KDC-237SA/237SAY
KDC-237SG/237SGY
4. In case of applying a new ROM correction when front-end
(A1) is replaced (There is ROM correction data.)
5. In case of applying a new ROM correction even when front-
end (A1) is not replaced.
FRONT-
END (A1)
E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
E2PROM circuit pattern
q
ROM correction
Tuner adjustment
Other
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
w
Install new E2PROM. (E2PROM that has been updated with
ROM correction)
Turn power on.
Press and hold the [1] and [3] keys, press reset button. (Enter
the system in the test mode.)
Press [B.BOOST] key. (ROM data System enters data trans-
fer mode.)
Press [ ] (or [ ].) (Select WRT)
Press [ ] key for 1 second or longer. (Data transfer)
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
e
System µ-COM (IC1) copies
the ROM correction data on the
mother unit (X34-) into E2PROM
in the front-end (A1)
WRT OK1 W-O1
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
System µ-COM (IC1) copies
data in the front-end (A1) into the
E2PROM on the mother unit (X34-).
(ROM correction and other data)
READ OK R-OK
Press [ ] key. (Exit ROM
data transfer mode.)
Press [ ] (or [ ].) (Select READ)
Press [ ] key for 1 second or longer. (Data transfer)
In case of [4] In case of [5]
ROM DATATRANSFER PROCESSES

18
KDC-237SA/237SAY
KDC-237SG/237SGY
Press [ ] key. (Exit ROM data transfer mode.)
Turn power off.
Remove front-end (A1).
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
t
FRONT-
END (A1)
E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
r
Install new front-end (A1).
No ROM correction or other data status.
Turn power on.
Press and hold the [1] and [3] keys press reset button. (Enter
the system in the test mode.)
Press [B.BOOST] key.(Enter the system in ROM data transfer
mode.)
Press [ ] (or [ ].) (Select WRT)
Press [ ] key for 1 second or longer. (Data transfer)
Press [ ] key. (Exit ROM data transfer mode.)
FRONT-
END (A1)
E2PROM E2PROM
SYSTEM
µ-COM (IC1)
Mother unit (X34-)
y
System µ-COM (IC1) copies
data on the mother unit (X34-) into
E2PROM in the front-end (A1)
WRT OK W-OK
ROM DATATRANSFER PROCESSES

19
KDC-237SA/237SAY
KDC-237SG/237SGY
EDCBA
1
2
3
4
5
6
7
W4
66
B.BOOST
VOL AUD
ATT AUTO 1
117
23456SRC
AUX IN
AM FM
G
VCC
VO
RST
18
D40
D31
D7
D32
D33
D34
D35
D36
D37
D38
D39
D41
D42
D14
D18
D12
D15
D20
D13
D16
D22
D21
D17
D11
D19
D3
D6
D2
D5
D1
D4
D9/
D8
S2
ED1
J2
S1
IC3
SWITCH UNIT
X16-386x-xx (J76-0360-02)
BEBE
R96
C10
R74
R80
R81
R82
C16
R31
R32
R33
R34
R61
R62
R63
R72
C21
R21
R22
C11
C12
C15
R3
R4
W1 W2
C25 C24
CP11
R1
R2
R11
R13
R14
R15
R16
R17
R18
R19
R23
R70
R75
R78
W3
CP1
1
20
21
40
41
60 61
80
1
2
19
20
J1
D71
D72
D73
D74
D75
D76
D77
D79
Q1
Q2
IC1
SWITCH UNIT
X16-386x-xx (J76-0360-02)
J2-R
J2-L
KI4
KI1
KI2
KI5
KI3
LED+B
ILL D GND
PAN SW5V
KS1
KS4
GUARD
FL SW11 25V
PAN5V
CW
CCW
KS2
GUARD
AUX L
AUX G
AUX R
FL+B TDF DET
SW5
CE
RST
ESD GND
VFD DATAS
VFD CLK
VFD DATAF
VFD RST
REMO
KS3
X16-386x-xx
Ref. No. Address
IC1 4D
PC BOARD
(COMPONENT SIDEVIEW) (FOIL SIDEVIEW)
Refer to the schematic diagram for the values of resistors and capacitors.

20
KDC-237SA/237SAY
KDC-237SG/237SGY
FGHIJ
1
2
3
4
5
6
7
L401
R331
R202
R205
R206
R218
R225
R227
R309
R318
C11
C9
R105
R306
R317
R340
R965 R406
R598
TH1
R892
C3
C4
C12
C14
C101
C102
C202
C203
C204
C205
C806
C990
R221
R17
R104
R108
R111
R113
R115
R201
R203
R211
R212
R226
R228
R229
R320
R315
R409
R803
R806
R808
R952
R972
R347
R12
R13
R14
R16
R110
R114
R971
R204
R214
R964
R223
R301
R303
R316
R305
R307
123
224
1
127
226
2
R313
R310
R314
R312
R408
R599
R801
R802
R804
R805 R807
R901
R902
R903
R904
R905
R906
R915
R954
R967
R961
R891
R969
R308
R311
R207
R962
R335
R342
R319
R963
R793
R791
R970
R951
R955
R968
R953
1
12
EE
CC
CC
B
EEB
EEB
CC 28
1
1
20
34
12
30 31
1
80
51
50
81
100
BE
BE
BE
EB
BE
BE
BE
BE
BE
BE
BE
BE
BE
BE BE
D3
Q301
D110
Q402
Q1
D801
D101
Q4
Q101
Q102
Q103
Q104
Q105
Q801
D102
D104
Q3
Q7
Q9
Q901
Q902
Q903
D301
IC1
IC8
IC2 IC3
W14
W100
W304
W102
W54
W802
W18
C7
W55
R109
W30
W20
W301
W52
C2
C5
C6
C15
C401
W803
C809
C805
C807
W804
W36
W48
W47
W26
W27
W28
W45
R101
1
16
8
9
R102
R106
W21
R116
R219
W305
R208
W
6
W46
C301
C302
W66
C801
C802
C803
C804
C901
C902
C1
W42
W43
L1
C808
R1
W15
R2
R11/W5
R3
R15
R103
R107
R112
R209
R210
W51
W309
W308
R
R330
R332
R333
R334
R336
R
3
R
3
R
3
R
3
R609
R611
R908 R910
R911
R907
R914
R913
R909
R912
W901
W902
X1
X2
W23
W810
W811
W809
W903
W6
W4
W2
W7
W11
W8
W10
W9
W13
W12
W17
W19
R5
R4
W16
W805W806
W807
W808
W44
W68
W306
W812
W1
W3
W64
W63
W24
W22
W303
W302
R302
R304
W85
W49
W86
W57
W58
W307
R402
R403
W801
W59
W62
W25
W60
W29
R117
W61
W37
W38
W39
W40
W41
R220
W32
W33
W35
W31
R407
W34
W50
W56
W53
W65
W201
J3
D1
D103
J1
D4
D5
D109
D401
D404
D802
D803
Q2
D2
D7
D105 D901
D303
Q8
D108
D107
D106
D606
CN2
IC4
IC6
A-DATA
SEL2
NOISE
RST
CNVSS
O-CE
O-CLK
O-DATA
ROM-DET
DC-DET
SEL1
ELECTRIC UNIT X34-4672-78 (J76-0358-02)
PC BOARD (FOIL SIDEVIEW)