Pioneer KEH-1940 User manual

PIONEER CORPORATION 4-1, Meguro 1-Chome, Meguro-ku, Tokyo 153-8654, Japan
PIONEER ELECTRONICS SERVICE INC. P.O.Box 1760, Long Beach, CA 90801-1760 U.S.A.
PIONEER ELECTRONIC [EUROPE] N.V. Haven 1087 Keetberglaan 1, 9120 Melsele, Belgium
PIONEER ELECTRONICS ASIACENTRE PTE.LTD. 253 Alexandra Road, #04-01, Singapore 159936
C PIONEER CORPORATION 1999 K-ZZY. NOV. 1999 Printed in Japan
ORDER NO.
CRT2425
HIGH POWER CASSETTE PLAYER WITH FM/MW/LW TUNER
KEH-1940 X1M/EW
Service
Manual
CONTENTS
1. SAFETY INFORMATION............................................2
2. EXPLODED VIEWS AND PARTS LIST ......................2
3. BLOCK DIAGRAM AND SCHEMATIC DIAGRAM ..10
4. PCB CONNECTION DIAGRAM................................20
5. ELECTRICAL PARTS LIST........................................28
6. ADJUSTMENT.........................................................32
7. GENERAL INFORMATION.......................................34
7.1 DISASSEMBLY ..................................................34
7.2 PARTS ................................................................35
7.2.1 IC...............................................................35
7.2.2 DISPLAY ...................................................38
8. OPERATIONS AND SPECIFICATIONS....................39
KEH-1960 X1M/EW
KEH-1940/X1M/EW
-This service manual should be used together with the following manual(s):
Model No. Order No. Mech. Module Remarks
CX-644 CRT1800 2M Cassette Mech. Module:Circuit Description, Mech.Description, Disassembly

2
KEH-1940,1960
2. EXPLODED VIEWS AND PARTS LIST
2.1 PACKING
1
4
3
5
9
16
15
6
10
8
7
13
11
12
2
14
1. SAFETY INFORMATION
This service manual is intended for qualified service technicians; it is not meant for the casual do-it-yourselfer.
Qualified technicians have the necessary test equipment and tools, and have been trained to properly and safely repair
complex products such as those covered by this manual.
Improperly performed repairs can adversely affect the safety and reliability of the product and may void the warranty.
If you are not qualified to perform the repair of this product properly and safely; you should not risk trying to do so
and refer the repair to a qualified service technician.

3
KEH-1940,1960
NOTE:
-Parts marked by “*” are generally unavailable because they are not in our Master Spare Parts List.
-Screws adjacent to ∇mark on the product are used for disassembly.
-PACKING SECTION PARTS LIST
Part.No
Mark No. Description KEH-1940/X1M/EW KEH-1960/X1M/EW
1 Accessory Assy CEA1917 CEA1917
2 Screw CBA1304 CBA1304
3 Handle CNC5395 CNC5395
4 Bush CNV3930 CNV3930
* 5 Polyethylene Bag E36-615 E36-615
6 Polyethylene Bag CEG-162 CEG-162
7 Carton CHG3911 CHG3912
8 Contain Box CHL3911 CHG3912
9 Protector CHP1622 CHP1622
10 Protector CHP1623 CHP1623
11 Owner’s Manual CRD3094 CRD3094
12 Installation Manual CRD3096 CRD3096
* 13 Passport CRY1013 CRY1013
* 14 Warranty Card CRY1157 CRY1157
15 Case Assy CXB3520 CXB3520
16 Cord Assy CDE6212 CDE6212
-Owner's Manual
Model Part No. Language
KEH-1940/X1M/EW CRD3094 English, Spanish, German, French, Italian, Dutch
KEH-1960/X1M/EW
-Installation Manual
Model Part No. Language
KEH-1940/X1M/EW CRD3096 English, Spanish, German, French, Italian, Dutch
KEH-1960/X1M/EW

4
KEH-1940,1960
2.2 EXTERIOR

5
KEH-1940,1960
(1) EXTERIOR SECTION PARTS LIST
Mark No. Description Part No. Mark No. Description Part No.
1 Screw BSZ26P050FMC
2 Screw BSZ30P055FUC
3 Screw BSZ30P060FMC
4 Screw BSZ30P100FMC
5 Cord Assy CDE6212
6 Cap CKX-003
7 Case CNB2481
8 Holder CNC5704
9 Insulator CNM5025
10 Cushion CNM5210
11 Tuner Amp Unit CWM6740
12 Screw BSZ26P080FMC
13 Screw BSZ26P140FMC
14 FM/AM Tuner Unit CWE1466
15 Holder CNC6554
16 Plug(CN603) CKM1270
17 Connector(CN601) CKS3362
18 Connector(CN602) CKS3581
19 Antenna Jack(CN301) CKX1056
20 Panel CNB2246
21 Holder CNC5399
22 Holder CNC6216
23 Heat Sink CNC6217
24 Holder CNC6845
25 Holder Unit CXB2687
26 Chassis Unit See Contrast table(2)
27 Detach Grille Assy See Contrast table(2)
28 Screw BPZ20P120FZK
29 Button(EJECT) See Contrast table(2)
30 Button(REW) See Contrast table(2)
31 Button(FF) See Contrast table(2)
32 Button(CROSS) See Contrast table(2)
33 Button(TUNER/BAND) See Contrast table(2)
34 Button(1-6) CAC6300
35 Button(DETACH) See Contrast table(2)
36 Spring CBH1836
37 Spring CBH2307
38 Cover See Contrast table(2)
39 Keyboard Unit See Contrast table(2)
40 LCD(LCD901) CAW1568
41 Connector(CN901) CKS3580
42 Holder CNC8525
43 Sheet CNM6486
44 Lighting Conductor CNV5969
45 Rubber CNV5970
46 Connector CNV5972
47 Grille Unit See Contrast table(2)
48 Button CAC4836
49 Spring CBH1834
50 Spring CBH1835
51 Spring CBH2367
52 Bracket CNC6135
53 Bracket CNC6791
54 Arm CNV4692
55 Arm CNV4693
56 Arm CNV4728
57 Panel Unit See Contrast table(2)
58 Door See Contrast table(2)
59 Spring CBH1838
60 Panel See Contrast table(2)
61 Screw IMS20P030FZK
62 Fuse(10A) CEK1136
63 Cassette Mechanism Assy EXK3410
64 IC(IC501) TDA7384
65 Transistor(Q804) 2SD2395

6
KEH-1940,1960
(2) CONTRAST TABLE
KEH-1940/X1M/EW and KEH-1960/X1M/EW are constructed the same except for the following:
Part No.
Mark No. Description KEH-1940/X1M/EW KEH-1960/X1M/EW
26 Chassis Unit CXB4636 CXB4637
27 Detach Grille Assy CXB4671 CXB4672
29 Button(EJECT) CAC5870 CAC5871
30 Button(REW) CAC5872 CAC5873
31 Button(FF) CAC5874 CAC5875
32 Button(CROSS) CAC6295 CAC6296
33 Button(TUNER/BAND) CAC6297 CAC6298
35 Button(DETACH) CAC6301 CAC6302
38 Cover CNS5696 CNS5697
39 Keyboard Unit CWM6745 CWM6746
47 Grille Unit CXB4631 CXB4632
57 Panel Unit CXB4924 CXB4925
58 Door CAT2109 CAT2108
60 Panel CNS5211 CNS5212

7
KEH-1940,1960

8
KEH-1940,1960
2.3 CASSETTE MECHANISM ASSY

9
KEH-1940,1960
1 Screw BSZ23P050FMC
2 Washer CBG1003
3 Connector(CN1) CKS2829
4 Screw(M2x5) EBA1038
5 Screw(M2x2.5) EBA1037
6 Spring EBH1554
7 Spring EBH1555
8 Spring EBH1556
9 Spring EBH1603
10 Spring EBH1591
11 Spring EBH1559
12 Spring EBH1593
13 Spring EBH1561
14 Spring EBH1562
15 Spring EBH1563
16 Spring EBH1623
17 Spring EBH1565
18 Spring EBH1566
19 Spring EBH1567
20 Spring EBH1568
21 Spring EBH1569
22 Spring EBH1571
23 Spring EBH1579
24 Head Base ENC1475
25 Lever ENC1429
26 Lever ENC1430
27 Lever ENC1431
28 Lever ENC1432
29 Arm ENC1433
30 Arm ENC1434
31 Arm ENC1480
32 Arm ENC1493
33 Bracket ENC1477
34 Lever ENC1483
35 Arm ENC1524
36 Frame ENC1440
37 Holder ENC1441
38 Lever ENC1446
39 Lever ENC1478
40 Belt ENT1027
41 Gear ENV1504
42 Gear ENV1470
43 Gear ENV1471
44 Lever ENV1472
45 Gear ENV1510
46 Gear ENV1475
47 Gear ENV1512
48 Gear ENV1513
49 Gear ENV1502
50 Lever ENV1480
51 Lever ENV1487
52 •••••
53 Arm ENV1519
* 54 PCB ENP1161
55 •••••
56 Switch(FWD)(REV)(S3) ESH1006
57 Switch(Load)(S1) ESN1016
58 Switch(Mute)(S2) ESN1017
59 Head Assy(HD1) EXA1466
60 Motor Unit(M1) EXA1467
61 Flywheel Unit EXA1547
62 •••••
63 Arm Unit EXA1447
64 Arm Unit EXA1448
65 Arm Unit EXA1534
66 Reel Unit EXA1450
67 Pinch Holder ENV1466
68 Pinch Roller ENV1518
69 Pinch Holder ENV1467
70 •••••
71 Chassis Unit EXA1498
72 Arm ENV1524
73 Washer HBF-167
74-78 •••••
79 Cover ENC1452
80 Washer CBF1051
81 Spring EBH1592
Mark No. Description Part No. Mark No. Description Part No.
-CASSETTE MECHANISM ASSY SECTION PARTS LIST

KEY MATRIX
M
L
FWD
GND
HEAD
M
MOTOR
FWD
Lch
REV
Lch
FWD-L
REV-L
Q808
Q806
Q807
Q805
FM SWITCH AM SWITCH
FM AM
FIX+B
VCO
AMIF
EO
Q303
Q302
LOOP FILTER
313 654 51
X601
4.5MHz
25 24
EO
AMIF
VCOIN
FM
AM
XI
XO
SL
FMSD
14
12
SYSTEM CONTROLLER
IC 601 (1/2)
PE5107A
SL
FMSD
Q804
9V REGULATOR
FIX+B
Q803
Q802 B.U
SYSPW
ILL+B
ILL+B
IL901-903
FM
OSC
Q201 Q202
FMTV
AM
OSC
AMIFC
VCO
FM+B AM+B TUN+B
FMSD
25
26
19 20 15 17 21 14 13 6
7
9
18
41 9 10 14 15 17 19 47 1 2
19
43
40
28
30
31
252318
16
36
3238
6
34
Q3
FM RF T31
FM/AM MIX Q31 CF51 FM/AM IF CF52 FM IF CF53
FM IF T51
FMSL
AMSL
AMTV
AMRF/AGC CF232 AM IF
FM/AM PROCESSOR
IC 1 PA4023B FM PROCESSOR
IC 2 PA4024A
TUN-L
FIX+B
A
B
C
D
KEYBOAR
FM/AM TUNER UNIT
TUNER AMP UNIT
CN301
ANT
Q304
LW
LW
57
LW
CA
10
KEH-1940,1960
A
1234
B
C
D
1234
3. BLOCK DIAGRAM AND SCHEMATIC DIAGRAM
3.1 BLOCK DIAGRAM

11
KEH-1940,1960
5678
A
B
C
D
5678
IC 501
TDA7384
FL+
FL-
RL+
RL-
MUTE
STBY
FL
RL
POWER AMP 9
7
17
19
FL+
FL-
RL+
RL-
6
5
8
9
7
2
1
22
4
SYSPW
Q501
Q609
Q502
Q607
MUTE
Q608
DMINH
Q606
FUSE
10A
B.U
B.U
ACC
CE
VDD1
VDD2
VDD
Q603
Q604
Q605
Q801
IC 801
TPD1018F
B REMOTE
BRE
CN603
1
SYSPW 6
5
B.U
SYSPW
SYSPW
437
4039
CE
DMINH
MUTE
11
15
19
20
IC 401
SN761029DL
ELECTRONIC
VOLUME
VDT/VCK/VST
2
3
3
IC 201
LA3161P
CASSETTE
EQUALIZER
1
B.U
FIX+B
4
MUTE
Q601
63
TAPLD
12
NOR/REV
MCMUT
LOAD
B.U
MECPW
50
Q809
Q810
MECPW
MECHA
POWER SWITCH
MECHA MUTE
Q602
SWVDD
18
VDD
SWVDD
9
10 LCK
LDT
4
3
5
6
CN602
ILL+B
SW5V
SCK
SIO
4
3
5
6
IC 901
PDC045A
KEY/LCD
DRIVER
RES
SCK
SO
SI
VDD
24
17
15
14
13
TRIX
LCD 901
CAW1568
CN901
SYSTEM CONTROLLER
IC 601 (2/2)
PE5107A
MUTE SWITCH
LOAD SWITCH
FWD/REV
FWD/REV SWITCH
GND
1
10
6
8
4
9
1
10
6
8
4
9
CN601
FWD-L
REV-L
ILL+B
TUN-L
D
BOARD UNIT B REMOTE
BRE
ACC
BATTERY
FL+
FL-
RL+
RL-
CASSETTE PCB

12
KEH-1940,1960
A
1234
B
C
D
1234
A-a A-b
A-a A-b
A-b
A-a
Large size
SCH diagram
Guide page
Detailed page
SYSTEM CONTROLLER
EQ AMP
ELECTRONIC VO
TUNER AMP UNIT
A
FM/AM TUNER UNIT
B
CASSETTE PCB
D
-73dBs
-
AM : -26.0dBs
FM : -16.0dBs
A
D
3.2 OVERALL CONNECTION DIAGRAM(GUIDE PAGE)
Note: When ordering service parts, be sure to refer to “EXPLODED VIEWS AND PARTS LIST” or “ELECTRICAL PARTS
LIST”.
A-a

600µH
CEL 1547
(1940/X1M/EW)
CEL 1479
(1960/X1M/EW)
14V 40mA
FUSE
POWER AMP
B.REMOTE
OLUME
KEYBOARD UNIT
C
GND
RL
+
RR
+
FR
+
FL
+
RL
-
FL
-
FR
-
RR
-
ANT
UP
BACK
ACC
-29.0dBs
AM : -0.9dBs
FM : 9.1dBs
TAPE : -3.9dBs
TAPE : 22.1dBs
FM : 100% 35.1dBs
AM : 30% 24.1dBs
TAPE : 315Hz 0dB 22.1dBs
KEY/LCD DRIVER
13
KEH-1940,1960
5678
A
B
C
D
5678
A
A-b
C

14
KEH-1940,1960
A
1234
B
C
D
1234
ELECTRONIC VOLUME
TUNER AMP UNIT
A
FM/AM TUNER UNIT
B
-29.0dBs
AM : -26.0dBs
FM : -16.0dBs
A-a
A-a A-b
1
2

15
KEH-1940,1960
5678
A
B
C
D
5678
SYSTEM CONTROLLER
EQ AMP
CASSETTE PCB
D
-73dBs
A-a
A-a A-b
D
3
5
4

16
KEH-1940,1960
A
1234
B
C
D
1234
600µH
FUSE
POWER AMP
GND
RL
+
RR
+
FR
+
FL
+
RL
-
FL
-
FR
-
RR
-
ANT
UP
BACK
ACC
AM : -0.9dBs
FM : 9.1dBs
TAPE : -3.9dBs
TAPE : 22.1dBs
FM : 100% 35.1dBs AM : 30% 24.1dBs TAPE : 315Hz 0dB 22.1dBs
A-a A-b
A-b
1
2

17
KEH-1940,1960
5678
A
B
C
D
5678
CEL 1547 (1940/X1M/EW)
CEL 1479 (1960/X1M/EW)
14V 40mA
B.REMOTE
KEYBOARD UNIT
C
KEY/LCD DRIVER
A-b
A-a A-b
C
3
5
4

18
KEH-1940,1960
A
1234
B
C
D
1234
3.3 FM/AM TUNER UNIT
B
3
1
2
FM/AM TUNER UN
DSP-201M-A11F
B

19
KEH-1940,1960
5678
A
B
C
D
5678
B
R UNIT
A

4. PCB CONNECTION DIAGRAM
4.1 TUNER AMP UNIT
20
KEH-1940,1960
A
1234
B
C
D
1234
A
CORD ASSY
TUNER AMP UNIT
NOTE FOR PCB DIAGRAMS
1. The parts mounted on this PCB
include all necessary parts for
several destination.
For further information for
respective destinations, be sure
to check with the schematic
diagram.
2. Viewpoint of PCB diagrams
Capacitor
Connector
P.C.Board Chip Part
SIDE A
SIDE B
A