Pioneer KEH-P7850 User manual

PIONEER ELECTRONIC 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 ELECTRONIC CORPORATION 1998 K-ZZS. NOV. 1998 Printed in Japan
ORDER NO.
CRT2307
MULTI-CD CONTROL HIGH POWER CASSETTE PLAYER WITH FM/AM TUNER
KEH-P7850 X1N/ES
Service
Manual
NOTE:
-See the separate manual CX-631(CRT1640) for the cassette mechanism description.
-The cassette mechanism assy employed in this model is one of 2L series.
-Dolby noise reduction manufactured under license from Dolby Laboratories Licensing Corporation.
"Dolby" and the double-D symbol are trademarks of Dolby Laboratories Licensing Corporation.
CONTENTS
1. SAFETY INFORMATION ...........................................2
2. EXPLODED VIEWS AND PARTS LIST......................2
3. SCHEMATIC DIAGRAM ..........................................10
4. PCB CONNECTION DIAGRAM ...............................20
5. ELECTRICAL PARTS LIST .......................................30
6. ADJUSTMENT ........................................................36
7. GENERAL INFORMATION ......................................38
7.1 PARTS.................................................................38
7.1.1 IC ...............................................................38
7.1.2 DISPLAY ...................................................43
7.2 DIAGNOSIS........................................................44
7.2.1 DISASSEMBLY.........................................44
7.2.2 TEST MODE .............................................45
7.3 BLOCK DIAGRAM..............................................48
8. OPERATIONS AND SPECIFICATIONS ...................49

2
KEH-P7850
2. EXPLODED VIEWS AND PARTS LIST
2.1 PACKING
20
19
15
12
16
17
4
7
11
3
10
9
8
6
5
2
14
18
13
1
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-P7850
1 Cord Assy CDE5758
* 2 Accessory Assy CEA2350-/N
3 Spring CBH1650
4 Screw Assy CEA2351
5 Screw CBA1304
* 6 Polyethylene Bag CEG-127
7 Screw CRZ50P090FMC
8 Screw TRZ50P080FMC
* 9 Polyethylene Bag CEG-158
10 Handle CNC5395
11 Bush CNV3930
12 Polyethylene Bag CEG-162
13 Battery CEX1030
14 Carton CHG3552
15 Contain Box CHL3552
16 Protector CHP2101
17 Protector CHP2102
18 Remote Control Assy CXB3456
19 Case CXB3520
20-1 Owner’s Manual CRD2762
20-2 Owner’s Manual CRD2763
20-3 Installation Manual CRD2764
Mark No. Description Part No. Mark No. Description Part No.
-PACKING SECTION PARTS LIST
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.
-Owner's Manual, Installation Manual
Model Part No. Language
KEH-P7850/X1N/ES CRD2762 English, Spanish, Portuguese(B)
CRD2763 Chinese, Arabic
CRD2764 English, Spanish,
Portuguese(B), Chinese, Arabic

4
KEH-P7850
2.2 EXTERIOR

5
KEH-P7850
1 Screw BMZ30P040FMC
2 Screw BSZ26P050FMC
3 Screw BSZ30P050FMC
4 Cord Assy CDE5758
5 Fuse(10A) CEK1136
6 Case CNB2350
7 Holder CNC6798
8 Shield CNC7365
9 Spacer CNM5488
10 Panel CNS5148
11 Cap CNV2680
12 Screw BSZ30P050FMC
13 Screw BSZ30P200FMC
14 Cord CDE5176
15 •••••
16 Holder CNC5704
17 Cushion CNM4870
18 Insulator CNM6275
19 Insulator CNV5793
20 Tuner Amp Unit CWM6147
21 Screw BMZ26P040FMC
22 Screw BPZ26P060FMC
23 Screw BSZ26P060FMC
24 Screw BSZ26P160FMC
25 •••••
26 Pin Jack(CN301) CKB1028
27 Terminal(CN403) CKF1059
28 Plug(CN951) CKM1231
29 Plug(CN604) CKS-783
30 Connector(CN601) CKS1499
31 Connector(CN751) CKS3408
32 Connector(CN602) CKS3568
33 •••••
34 Connector(CN302) CKS3598
35 Antenna Jack(CN402) CKX1056
36 Panel CNB2358
37 Heat Sink CNC7991
38 Holder CNC7996
39 Holder CNC7997
40 Case CNC7998
41 Case CNC8254
42 Holder CNC8255
43 Case CNC8350
44 Case CNC8351
45 Insulator CNM6099
46 Insulator CNM6190
47 Insulator CNM6257
48 Heat Sink CNR1505
49 Insulator CNV5792
50 FM/AM Tuner Unit CWE1486
51 Holder CNC6554
52 Chassis Unit CXB3048
53 Screw ISS26P055FUC
54 Detach Grille Assy CXB3439
55 Screw BPZ20P060FMC
56 Screw BPZ20P080FZK
57 Button(OPEN) CAC5804
58 Button(EJECT) CAC5805
59 Button(SOURCE) CAC5806
60 Button(BAND) CAC5807
61 Button CAC5808
62 Button(DISP) CAC5809
63 Button(1-6) CAC5922
64 Spring CBH2205
65 Cover CNS5146
66 Holder CNV5537
67 Keyboard Unit CWM6061
68 LCD(LCD901) CAW1502
69 EL CEL1587
70 Connector(CN901) CKS2733
71 Holder CNC7992
72 Tape CNM6348
73 Spacer CNM6347
74 Connector CNV5536
75 Grille Unit CXB3483
76 Screw BPZ20P060FMC
77 Screw CBA1082
78 Screw CBA1176
79 Washer CBF1001
80 Spring CBH2063
81 Spring CBH2204
82 Cord CDE5800
83 Connector CKS2780
84 Roller CLA3386
85 Cushion CNM5486
86 Sheet CNM6109
87 PCB CNP5430
88 PCB CNP5444
89 Panel CNS5147
90 Holder CNS5157
(1) EXTERIOR SECTION PARTS LIST
Mark No. Description Part No. Mark No. Description Part No.

6
KEH-P7850
91 Holder CNS5165
92 Holder CNS5389
93 Switch(S602) CSN1027
94 Holder Unit CXB3049
95 Holder Unit CXB3050
96 Holder Unit CXB3051
97 Damper Unit CXB3180
98 Screw IMS20P040FZK
99 Remote Control Unit CXB3456
100 Cover CNS4948
101 •••••
102 Cassette Mechanism Module EXK3990
103 Coil(L801) CTH1227
104 IC(IC301) PAL005A
105 Transistor(Q951) 2SD2396
Mark No. Description Part No.

7
KEH-P7850

8
KEH-P7850
2.3 CASSETTE MECHANISM MODULE

9
KEH-P7850
1 Screw BSZ20P040FMC
2 Washer CBF1037
3 Washer CBF1038
4 Washer CBG1003
5 Deck Unit EWM1018
6 Screw EBA1028
7 Screw EBA1037
8 Spring EBH1531
9 Spring EBH1575
10 Plug(CN251) CKS3540
11 Spring EBH1515
12 Spring EBH1587
13 Spring EBH1517
14 Spring EBH1518
15 Spring EBH1519
16 Spring EBH1537
17 Cord EDD1020
18 Photo-interrupter(EGN2,3) EGN1006
19 Photo-interrupter(EGN1) EGN1005
20 Roller ENR1031
21 Shaft ELA1373
22 Pinch Roller ENV1518
23 Arm ENC1489
24 Arm ENC1397
25 Guide ENC1481
26 Holder ENC1417
27 Lever ENC1448
28 Arm ENC1488
* 29 Motor EXM1031
30 Belt ENT1027
31 Gear ENV1347
32 Collar ENV1508
33 Gear ENV1350
34 Flywheel ENV1500
35 Worm Gear ENV1439
36 Worm Wheel ENV1440
37 Gear ENR1037
38 Lever ENV1442
39 Arm ENV1525
40 Gathering PCB ENX1037
41 Gathering PCB ENX1042
42 Switch(S1,S2) ESG1004
43 Motor Unit(M2) EXA1485
44 Chassis Unit EXA1567
45 Pinch Holder ENV1485
46 Pinch Holder ENV1486
47 Reel Unit EXA1543
48 Head Base Unit EXA1457
49 Lever Unit EXA1438
50 Gear Unit EXA1545
51 Frame Unit EXA1458
52 Lever Unit EXA1439
53 Head Assy(HD1) EXA1506
54 Motor Unit(M1) EXA1490
55 Washer HBF-179
56 Screw BMZ20P022FMC
57 Spring EBH1545
58 Washer YE20FUC
59 Pinch Holder Unit EXA1529
60 Pinch Holder Unit EXA1528
Mark No. Description Part No. Mark No. Description Part No.
-CASSETTE MECHANISM MODULE SECTION PARTS LIST

10
KEH-P7850
A
1234
B
C
D
1234
3. SCHEMATIC DIAGRAM
3.1 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-aA-a A-bA-b
A-aA-a A-bA-b
A-bA-b
A-aA-a
Large size
SCH diagram
Guide page
Detailed page
AC
A-a
B
C
D E F MODULE
ANTENNA JACK

11
KEH-P7850
5678
A
B
C
D
5678
A-b
A
A

12
KEH-P7850
BANTENNA JACK
A
1234
B
C
D
1234
A-a
A-a A-b

13
KEH-P7850
C
DEFMODULE
5678
A
B
C
D
5678
A-a
A-a A-b
C

14
KEH-P7850
A
A
1234
B
C
D
1234
A-a A-b
A-b

15
KEH-P7850
5678
A
B
C
D
5678
A-b
A-a A-b

16
KEH-P7850
3
1
2
FM/AM TUNER UN
D1D2 RD39JSRD39JS
R1
R2
2R2M
2R2M
D6 MA157
A
1234
B
C
D
1234
3.2 FM/AM TUNER UNIT
B
B

17
KEH-P7850
ER UNIT
IFC
5678
A
B
C
D
5678
B
A

18
KEH-P7850
DECK UNIT
MUTE
CXA2560Q
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29 28 27
26 25
24
23
22 21
1
2 3 4
5 6
7
8
9 10
CN602
R256 220
R287
0R0
C273
22/16
R283 0R0
R284 0R0
R282 0R0
C253 330P
C254 330P
C252 330P
C251 330P
R281 0R0
R255 220
C256
R01
R258
1K
VR302
CCP1280
33K(B)
R301
18K
C310 R1
R273 1K
R274 1K
R271 1K
R272 1K
R290 0R
C403 R0
R403 82
C402
4700P
C401
R33
R40
R40
4R7
R323 0R0
R257
1K
C255
R01
C272 R1
VR301
33K(B) CCP1280
C309 R1
C313 100P
R386 0R0
R285 0R0
HD1
HEAD ASSY
EXA1506
TEST TAPE
NCT-150
(400Hz, 200nWb/m)
RL
RR
FR
FL
Signal GND
C302
R1
C302
R1
C301
R1
R322 1K
-6dBs(388mV)±1dB
D
A
Fwd
Fwd
Rev
Rev
A
1234
B
C
D
1234
3.3 CASSETTE MECHANISM MODULE
D

19
KEH-P7850
PCB UNIT
REEL PCB
SWITCHES:
PCB UNIT
S1:LOAD SWITCH..........EJECT-PLAY
S2:70µs SWITCH............ON-OFF
The underlined indicates the switch position.
R290 0R0
C403 R068
R403 82K
C402
4700P
C401
R33
R402
16K
R401
4R7K
R351 1K
R352 1K
R353 1K
R354 1K
R373 0R0
R375 0R0
R355 270K
C352 3900P
R362 180
C351 R22
C353 R01
C354 R01
R374 0R0
C356 R01
C355 R1
D352 1SS355
M1
MOTOR UNIT
(MAIN MOTOR)
EXA1490
S1 LOAD
ESG1004 S2
ESG1004
70µs
MODE
SENSE
EGN1
EGN1005
EGN2
EGN1006
FWD END
SENSE
EGN3
EGN1006
REV END
SENSE
M2
MOTOR UNIT
(SUB MOTOR)
EXA1485
Power GND
F
E
5678
A
B
C
D
5678
D E F

20
KEH-P7850
CORD ASSY
PRE OUT
(FRONT)
CORD
A
1234
B
C
D
1234
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 dia-
gram.
2. Viewpoint of PCB diagrams
4. PCB CONNECTION DIAGRAM
4.1 TUNER AMP UNIT
A
A
Capacitor
Connector
P.C.Board Chip Part
SIDE A
SIDE B
TUNER AMP UNIT