IC1LCD driverLCD derive & Key input interface
IC2SensorRemote control sensor
Q1Key scan detectkey scan start at base gose “L”.
Q2LED SWWhen Q2 base gose “H” LED is light on RED Color
Q3LED SWWhen Q2 base gose “H” LED is light on GREEN Color
IC1System control ICSystem control microprocessor
IC4Audio power ICAudio power amplifier
IC6RDS decoderRDS decoder IC
IC7Power supply ICMulti AVR IC (for 5V, 8V, P-CON & P-ANT)
IC8Muting logic ICControl for MUTE, P-ANT & RESET muting
IC10E-VOL & tuner ICE-VOL. FM/AM tuner & stereo decoder
IC11Reset ICWhen BU5V line voltage is less than 3.5V, this IC output line is “L”
IC12E2PROMMemorized tuner adjustment data (save & load)
Q10BU detectorWhen the base goes “H” during BU applied (ON)
Q20ACC detectorWhen the base goes “H” during ACC applied (ON)
Q40Muting driver foe Q223, 224When the base goes “L” (Muting : ON)
Q50SW5VWhen the base goes “L” (SW5V : ON)
Q51SWControl SW for IC7
Q55SERVO +B AVRServo AVR (7.4V)
Q70Serge detectorWhen the base goes “H” (Serge detection)
Q101DSI illumination SWWhen the base goes “L” (DSI illumination : ON)
Q102Panel 5V SWWhen the base goes “L” (Panel 5V : ON)
Q201Noise bufferTuner audio noise buffer amplifier
Q223,224Preout muting SWWhen the base goes “H” (Preout muting : ON)
Q251SWWhen the base goes “L” (IC4 : ON)
Q252Smeter RC & MPTHTC SWRC & TC is “LONG” when the base is “H” (base is “L” is AF search)
Q253Smeter RC & MPTHTC SWWhen collector is “H”, emitter is “H”
Q501AM RF amplifierWhen the base goes “H” (RF circuit gain is up)
Q502FM RF amplifierWhen the base goes “H” (RF circuit gain is up)
Q503MPX bufferMPX input buffer with RDS
4
KDC-2027SA/SAY/SG/SGY, 3027A/AY/G/GY
KDC-308A/AY/G/GY, 4027/V/VY/Y, F327A/G
MICROCOMPUTER’S TERMINAL DESCRIPTION
● SYSTEM MICROCOMPUTER : UPD780058GC55x (X34 : IC1)
Pin No.NameI/ODescriptionProcessing Operation
1PANELIPanel detectionH : Panel detached, L : Panel attached
28EJE SWI
3NCONot used (out put L)
4Avss
5L-RSTOLCD driver RESETNormal H, Power off L
6L-CEOLCD driver selection
7AVREF1
8NCNot used (connected to 9pin)
9IC10-DATAI/OIC10, E2PROM data communicationNon communication : H
10IC10-CLKOIC10, E2PROM clock communicationNon communication : H
11L-DATALIData input from the LCD driverWhen panel detached : L
12L-DATASOData output to the LCD driverWhen panel detached, output L
13L-CLKOClock output to the LCD driverWhen panel detached, output L
14R-DATAIData input from the RDSExcept RDS model : Output L
15R-QUALIQuality input from the RDSExcept RDS model : Output L
16CH-DATACIData input from the changer (new 5L)Except changer model : Output L
17CH-DATAHOData output to the changer (new 5L)
18CH-CLKI/OClock input/output with the Changer (new 5L)
19CH-REQHORequest output to the changer (new 5L)
20NCONot used (output L)
21AFSONoise detection time constant switching terminal
22~24 NCONot used (output L)
25CH-CONTOChanger control
26TYPE REFO5V lines output for destination settingH : During destination reading
27SDITuner SD inputH : Station detected
28NCONot used (output L)
29TYPE2IDestination type selection terminal 2Refer to destination type list.
30TYPE1IDestination type selection terminal 1Refer to destination type list.
H : Eject is completed
Except 8cm CD model : Always output L
H : Panel detached, L : RESET
When 7seg model, output L
H : Select (panel communication)
When panel attached, output L
Non communication : H
Pull down on X34 unit, Pull up on X16 unit
When non communication, last data keeping
Except changer model : Output L
Check the old and new
Except changer model : Output L
L : Requset
Except changer model : Output L
H : Normal, L : FM/AM seek and AF search
(When tuner SRC auto zero, L)
H : Changer on, L : Changer off
Except changer model : Output L
31TYPE0IDestination type selection terminal 0Refer to destination type list.
32TUNER-TYPE1IDestination available/genuine model rool offH : Genuine model 1, L : Available model
33Vss1
34TUNER-TYPE0IDestination available/genuine model noise cancelH : Genuine model 0, L : Available model
35MUTEOMute (E.Vol, Preset) control
36M-DATAI/OData input/output with the CD mechanismNon communication : H
37M-CLKOClock output to the CD mechanismNon communication : H
41P-STBYOPower IC standby controlH : Power IC ON, L : Power IC OFF
42SW5VOSW 5V control
43B.U-DETIBack up detection terminalH : Power down, L : B.U. on
44ACC-DETIACC detection terminalH : ACC OFF, L : ACC ON
H : Mute on, L : Mute off
Power off after that 15 second L
When adjustment = H
IC10-DATA, CLK=Hi-z
H : Mute off, L : Mute on
Power off after that 15 second H
H : When momentary power down detected
L : Nomal
H : SW5V OFF, L : SW5V ON
Power off after that 10 second H
45PS1-0O
46PS1-1O
47PS1-2OPower supply IC SW1 control 2 P-ANT
48PS2-0O
49PS2-1O
50BEEPBEEP
51DSIODSI control
52NCONot used (out put L)
53NCONot used (out put L)
Power supply IC SW1 control 0
Audio 8V, P-CON
Power supply IC SW1 control 1
Audio 8V, P-CON
Power supply IC SW2 control 0
ILLUMI, FM, AM
Power supply IC SW2 control 1
ILLUMI, FM, AM
BA4911 SW1Power supply IC output
PS1-2 PS1-1 PS1-0A8V P-CON P-ANT
LLLSTANDBY
LL (H)H (L)ONOFFOFF
LHHONONOFF
HHHONONON
BA4911 SW2 Power supply IC output
PS2-1 PS2-0 ILLUMI FMAM
LLSTANDBY
L (H)H (L)ONONOFF
HHONOFFON
H : Light on, L : Light off
When panel attached, output L
When panel detached, flashing at the panel (H/L)
FIX model is output L
6
KDC-2027SA/SAY/SG/SGY, 3027A/AY/G/GY
KDC-308A/AY/G/GY, 4027/V/VY/Y, F327A/G
MICROCOMPUTER’S TERMINAL DESCRIPTION
Pin No.NameI/ODescriptionProcessing Operation
54LOE/LIM SWICD mechanism down&limit detectionH : Chucking detection, L : Normal
55MO SWOCD mechanism loading motor control outputH : Loading, Eject, Break, L : Play
56LO/EJI/OCD mechanism loading/Eject switching terminalH : Eject, L : Loading
57M-STOPOStop output to the CD mechanismH : Play, L : Stop
58M-RSTOReset output to the CD mechanismH : Normal, L : CD mechanism reset
59M-MUTEIMute input from the CD mechanismH : Mute off, L : Mute on
60RESETReset input from the System microcomputer
61REMOIRemote control input
62R-CLKIRDS clock inputExcept RDS model : Output L
H : Changer detection
63CH-REQCIRequest input from the changer (new 5L)L : Request
● CD MECHANISM CONTROL IC : 789166YGB-A513 (X32 : IC1)
Pin No.NameI/ODescriptionProcessing Operation
1~6NCINCGND
7ZMUTE_LI0 bit MUTE detect (Lch)
8ZMUTE_RI0 bit MUTE detect (Rch)
9AVss-DGND
10/MUTE_LOLch Audio mute controlL : MUTE ON, H : MUTE OFF
11/MUTE_RORch Audio mute controlL : MUTE ON, H : MUTE OFF
12/MSTOPIInterruption for stand-byL : STOP, H : Release for STOP mode
13INTQIInterruption for DSP ICH : Interruption
14/FOGUPIInterruption for focus gain upL : Fo GAIN UP, H : NORMAL
15PONOPower ON/OFF controlH : ON, L : OFF
16/SCKO(for DSP) serial data clock output
17Vdd1-BU5V
18SOO(for DSP) serial data output
19SII(for DSP) serial data input
20/CLKI/O(for system control) I2C clock
21DATAI/O(for system control) I2C data
22Vpp-(FLASH saving terminal)
23XT2-NCOPEN
24XT1INCGND
25/MRESETIReset detectL : RESET, H : NORMAL
26X2-System clock4.19MHz
27X1ISystem clock4.19MHz
28Vss0-DGND
29Vdd0-BU5V
30LOE&LIM_SWILoading end & limit SW detectL : Inside detect, H : Outside
31DRV_MUTEODriver mutingL : MUTE ON, H : MUTE OFF
32,33 NCONCOPEN
34/SERCHOCondition of serch stateL : Search, H : NORMAL
35/STBOData strobe signal output
36A0OCommand & parameter signal output
37Vss1-DGND
38/DSP_RESETODSP reset controlL : RESET, H : NORMAL
39~41 NCONCOPEN
42/PONOPow er ON/OFF controlL : ON, H : OFF
43Avdd-BU5V
44Avref-BU5V
Less than 54h : NORMAL,
More than 54h : ZMUTE detect
Less than 54h : NORMAL,
More than 54h : ZMUTE detect
8
KDC-2027SA/SAY/SG/SGY, 3027A/AY/G/GY
KDC-308A/AY/G/GY, 4027/V/VY/Y, F327A/G
TEST MODE
1. How to enter test mode
While holding the FM key and preset 6 ke y and reset the unit.
All display segments light up when the test mode is entered.
2. How to exit from test mode
Reset the unit.
Turning ACC off, power off, momentary power down or panel
detaching does not terminate the test mode.
3. Test mode specifications of CD receiver
• Pressing the Track Up key skip to tracks in the following se-
• Pressing the Track Down key skip to the track immediately
before the track being played.
• Pressing Preset 1 key skip to track No. 28.
•Forced ejection is not provided.
4. Audio functions
• Pressing the AUDIO key or the “*” key on the remote con-
troller initiates the Audio adjustment mode.
• In the Audio adjustment mode, the Seek Up/Down keys on
the remote controller can only be pressed shortly. (They cannot be held depressed.)
• The volume is -10dB (which is displayed as “30”).
• LOUDNESS is OFF.
• The Bass/Treble Up/Down and Balance/Fader Up/Down
buttons function as full-boost/full-cut and full-front/full-rear
respectively.
5. Menu mode (for 14segment model)
• Pressing the CLK or the DNPP k ey on the remote controller
initiates the Menu mode.
• In the Menu mode, the Seek Up/Down keys on the remote
controller can only be pressed shortly. (They cannot be held
depressed.)
• With the models incorporating RDS, the first oper ation in the
menu becomes local seek.
6. Version and operating hours display
• The following table shows the key operations and resulting
display information.
Key OperationDisplay
Pressing Preset 1Version (Date and time display)
Pressing Preset 2All display segments light up
Pressing Preset 3CD operating hours
Pressing Preset 4E2PROM (Adjustment data for IC10)
Pressing Preset 5CD ejection count
Pressing Preset 6Number of times adjustment for IC10
• Holding Preset 3 while the oper ating hour inf ormation is displayed clears it.
• Holding Preset 5 while the ejection count information is displayed clears it.
Adjustment Mode
• Adjustable items
1 : Stereo DecoderSub address : 9
2 : ConfigurationSub address : D
3 : Stereo decoder AdjustmentSub address : E
4 : Hi-CutSub address : C
5 : Field strength controlSub address : B
• Default values
If they are not written in the EEPROM, the default values
specified are set in IC10.
Adjustment procedure
1. Enter the IC10 Adjustment mode by resetting the unit while
holding preset 3 key + preset 6 key.
2. Select the TUNER source by pressing SRC.
3. When the adjustment mode is entered, the display shows
2-digit hex number.
4. When preset 1~5 is recalled, the setting values corresponding to the pressed number are displayed. (The displayed
values are those in the RAM.)
5. Vary each setting value using
6. Store the values in the corresponding preset number.
7. The settings can be performed individually for each item.
(It is not required to store all the values together.)
8. After storing the values, reset the unit to exit from the adjustment mode. The v alues set in the EEPROM will be read
during the resetting.
9. When the band is switched, there may be cases in which
the preset number being displayed does not coincide with
the stored setting value. To check this, be sure to recall the
preset number after you switch the band.
and key.
Notes
1. The items that are not stored will be set to the default values.
2. Once a value is stored in memory, the value will always be
used later.
(It is not allowed to modify the setting values by switching
the destination type.)
M : AM Adjustment
For Your Information :The frequency of SET is only set up
by Pre-Set-Ke y in case this adjustment
1-2. Adjustment of 1st & 2nd-MIX Coil
Voltage Check Point:S-METER-Check Land
(PWB Side B, around W572)
Adjustment Coil:1
Setting of Signal Generator : Refer to the following tables
TYPEMODEfreq.Mod.ANT InputFig
KAM1000kHzOFF35dBuEMF(B),(C)
E,M,JAM999kHzOFF35dBuEMF(B),(C)
qThe appearance and the coil with which S-METER DC
voltage serves as the maximum are turned and adjusted
in the above-mentioned SG input.
wBy the above-mentioned adjustment method, same ad-
justment is performed to both sides (1st & 2nd MIX Coil).
(
REAR VIEW
st IFT = L508 / 2nd IFT = L509
)
1-3. Adjustment of FM_ANT&RF Coil
Voltage Check Point: S-METER-Check Land
Adjustment Coil: ANT Coil = L505
Setting of Signal Generator : Refer to the following tables.
TYPE MODEfreq.Mod.ANT InputFig
E/MFM87.5MHzOFF5 or 11dBuEMF(A),(C)
KFM87.9MHzOFF5 or 11dBuEMF(A),(C)
JFM76.0MHzOFF5 or 11dBuEMF(A),(C)
qThe appearance and the coil with which S-METER DC
voltage serves as the maximum are turned and adjusted
in the above-mentioned SG input.
wBy the above-mentioned adjustment method, same ad-
justment is performed to both sides (ANT & RF Coil).
1-4.
Adjustment of STEREO (adjustment of 456k-VCO)
Adjust in TEST MODE
•How to enter the test mode
While pressing on [FM] and [PRESET 6] keys, reset the
unit.
• Adjustment method
Complete on condition that show “ALL OFF” when pressing on [PRESET 1] and [PRESET 6] keys.
(Writing adjustment valve to the EEPROM.)
Effect of adjustment is in cofirmation of adjustment status
at [PRESET 4] key.
• Display of [PRESET 4]
Adjustment “OK” : 14seg model “E2P OK” 7seg model
“EPO”
Adjustment “NG” : 14seg model “E2P ERR” 7seg model
“EPE”
• Releasing the test mode
Reset mode only.
ACC off, Power off, Power down and Remove the panel
mode is not releasing.
(PWB Side B, around W572)
RF Coil = L506
10
L506
L508
L505
L509
L507
[Fig.1]
(
OVER VIEW
[Fig.2]
(
TUNER ANT
)
)
(A)
FM-SG
(B)
AM-SG
(C)
DC Voltmeter
S-METER
Check Land
(
UNDER VIEW
[Fig.3]
Vt
Check Land
)
IC10
KDC-2027SA/SAY/SG/SGY, 3027A/AY/G/GY
KDC-308A/AY/G/GY, 4027/V/VY/Y, F327A/G
ADJUSTMENT
2. IC10 (TDA7513T) Replacement - Parts vs Adjustment Item Table
• When the parts in the following tables are exchanged, please readjust according to a table.
• When other parts are exchanged, please perform only a check of operation. There is no necessity for readjustment.