Pioneer XR-A770 User manual

ORDER NO.
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
PIONEER ELECTRONIC CORPORATION 1998
RRV2054
CONTENTS
T – ZZK NOV. 1998 Printed in Japan
1. SAFETY INFORMATION ...................................... 2
2. EXPLODED VIEWS AND PARTS LIST................ 3
3. SCHEMATIC DIAGRAM ..................................... 14
4. PCB CONNECTION DIAGRAM.......................... 31
5. PCB PARTS LIST ............................................... 44
6. ADJUSTMENT .................................................... 49
7. GENERAL INFORMATION ............................... 55
7.1 PARTS ......................................................... 55
7.1.1 IC ......................................................... 55
7.1.2 DISPLAY.............................................. 61
7.2 DISASSEMBLY ........................................... 63
7.3 BLOCK DIAGRAM....................................... 66
8. PANEL FACILITIES AND SPECIFICATIONS.... 68
STEREO CD CASSETTE DECK RECEIVER
XR-A770
THIS MANUAL IS APPLICABLE TO THE FOLLOWING MODEL(S) AND TYPE(S).
Type Model Power Requirement Remarks
XR-A770
MYXJ AC220-230V
NVXJ AC230V

2
XR-A770
Printed on the Rear Panel
NVXJ Type
MYXJ Type
MYXJ Type
LABEL CHECK
Additional Laser Caution
1.Laser Interlock Mechanism
The position of the switch (S8501) for detecting loading
state is detected by the system microprocessor, and
the design prevents laser diode oscillation when the
switch (S8501) is pressed physically.
Thus,theinterlockwillnolongerfunctioniftheswitch(S8501)
is released physically and deliberatery.
The interlock also does not function in the test mode ∗ .
Laser diode oscillation will continue, if pin 62 of
LA9240ML (IC8101) on the CD ASSY mounted on the
$M Loading Mechanism assembly is connected to GND,
or else the terminals of Q8101 are shorted to each other
(fault condition).
2.Whenthecoverisopened,close viewing of the objective
lens with the naked eye will cause exposure to a Class
1 laser beam.
∗ : Refer to page 54.
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.
IMPORTANT
THIS PIONEER APPARATUS CONTAINS
LASER OF CLASS 1.
SERVICING OPERATION OF THE APPARATUS
SHOULD BE DONE BY A SPECIALLY
INSTRUCTED PERSON.
LASER DIODE CHARACTERISTICS
MAXIMUM OUTPUT POWER: 1.3 mW
WAVELENGTH: 790 nm ±25 nm

3
XR-A770
VOL
KARAOKESFC
DISC DISC DISC
CLEAR
STATION
REMOTECONTROLUNIT CU-XR025
MONO BAND
PGM
REPEATRANDOM
AUX
P.BASSDISPLAY
SLEEP
POWER
6
1
3
7
9(1/2)
8(1/2)
8(2/2)
9(2/2)
10
2
13 14
11
15
4
5
1819
16
MYXJ Type Only
MYXJ
Type Only
MYXJ
Type Only
MYXJ
Type Only
NVXJ Type Only
17
13
9
12
2.1 PACKING
1 FM Antenna ADH7005
2 Operating Instructions XRE3014
(English/French)
3 AM Loop Antenna XTB3001
4 Remote Control Unit XZN3007
(CU-XR049)
5 Battery Cover AZA7204
NSP 6 Dry Cell Battery (R6P, AA) VEM-013
7 Polyethylene Bag Z21-038
(0.03 ×230 ×340)
8 Front Pad See Contrast table (2)
9 Rear Pad See Contrast table (2)
(1) PACKING PARTS LIST
Mark No. Description Part No.
2. EXPLODED VIEWS AND PARTS LIST
NOTES: •Parts marked by "NSP" and can not be supplied.
•The mark found on some component parts indicates the importance of the safety factor of the part.
Therefore, when replacing, be sure to use parts of identical designation.
•Screws adjacent to mark on the product are used for disassembly.
10 Packing Case See Contrast table (2)
11 Packing Sheet AHG7049
12 Fuse (T5A) See Contrast table (2)
13 Power Cord See Contrast table (2)
NSP 14 Polyethylene Bag See Contrast table (2)
15 Operating Instructions XRE3016
(English/French/German/Italian/Dutch/
Swedish/Spanish/Portuguese/Chinese)
NSP 16 Door Spacer XHG3002
NSP 17 Warranty Card ARY7022
18 Operating Instructions See Contrast table (2)
19 Operating Instructions See Contrast table (2)
Mark No. Description Part No.
(2) CONTRAST TABLE
XR-A770/MYXJ and NVXJ are constructed the same except for the following :
Mark No. Symbol and Description Part No. Remarks
XR-A770 XR-A770
/MYXJ /NVXJ
8 Front Pad XHA3005 XHA3009
9 Rear Pad XHA3006 XHA3010
10 Packing Case XHD3050 XHD3070
12 Fuse (T5A) Not used AEK1016
13 Power Cord ADG1154 ADG1156
NSP 14 Polyethylene Bag AHG7033 Not used
18 Operating Instructions (Italian/German/Dutch) XRC3003 Not used
19 Operating Instructions XRC3004 Not used
(Portuguese/Swedish/Spanish)

4
XR-A770
2.2 EXTERIOR (1/2)
212
12
Note :
Attatch on the same numbers ×three.
Refer to
"2.5 $M MECHANISM CD".
Note :
Hook Tray cap on top of loading tray and then
insert the bottom three hooks.
9
9
11
15
11
15
11
1
6
10
4
5
7
14
13
3
3
9
8
17
16
18
18

5
XR-A770
•EXTERIOR (1/2) PARTS LIST
Mark No. Description Part No.
1 22P F.F.C/30V XDD3018
NSP 2 $M Mechanism CD XXA3006
3 Volume Knob XAA3005
4 FL Cover A XAK3026
5 FL Cover B XAK3036
6 Tray Cap XZN3047
7 Display Panel XAK3049
8 Bonnet Case XZN3040
9 Screw BPZ30P100FZK
10 Pioneer Badge XZN3049
11 Screw VBT30P080FZK
12 Disc Label XAX3127
13 Jog Knob Assy XXG3023
14 Bass Knob XAB3005
15 Screw BCZ30P080FZK
NSP 16 Cord Stopper DNF1128
17 Push Rivet AEC7138
18 Cushion Rubber XEB3002

6
XR-A770
2.3 EXTERIOR (2/2)
b
b
d
a
a
aaa
a
a
bbb
b
bb
cccc
aa
Refer to
"2.4 FRONT PANEL SECTION".
8
17
19
19
19
29
22
7
11
33
19
19
13
27
35
27
16
34
30
38
28
28
2
3
5
4
9
10
14
15
25
36
21
19
18
20
1
19
24
24
19
26
23
24
19
24
24
24
11
22
39
40
12
43 NVXJ
Type only
41
MYXJ Type only
42
MYXJ
Type only
NVXJ
Type only

7
XR-A770
(1) EXTERIOR (2/2) PARTS LIST
Mark No. Description Part No.
1 AF Assy XWZ3120
2 SECONDARY Assy XWZ3121
3 PRIMARY Assy XWZ3152
4 FM/AM TUNER MODULE AXQ7068
5 Power Transformer (T1) XTS3018
6 • • • • •
7 Fuse (FU1 : T4A) AEK1060
NSP 8 Chassis XNA3001
9 DC Fan Motor AXM7003
10 Fan Plate ANG7153
11 PCB Bracket XNG3006
12 Ceramic Capacitor CKPUYB102K50
13 Heat Sink XNH3004
14 Wire Clip A XEC3003
15 Rear Panel XNC3012
16 Cord Stopper DNF1128
NSP 17 SUPPORT Assy XNP3009
18 Screw BBZ30P140FMC
19 Screw VBZ30P080FZK
NSP 20 Tweeter Cover XAK3069
21 Screw ASZ40P060FMC
22 Binder ZCA-SKB90BK
23 Earth Plate XNG3015
24 Screw BPZ30P100FZK
25 Screw BBZ30P300FMC
NSP 26 Name Label See Contrast table (2)
27 Screw BBZ30P060FMC
28 Screw IBZ30P135FMC
29 SUB TRANS Assy XWZ3139
30 REAR AMP Assy XWZ3122
31 • • • • •
32 • • • • •
33 H.S.Bracket XNG3007
34 FET Bracket XNG3009
35 H.S.Support XNG3014
36 Wire Clip B XEC3004
37 • • • • •
38 Mica Sheet XEE3002
39 Locking Spacer XEC3009
40 Card Spacer XEC3008
41 Caution Label HE See Contrast table (2)
42 Caution Label See Contrast table (2)
43 Caution Label See Contrast table (2)
Mark No. Description Part No.
(2) CONTRAST TABLE
XR-A770/MYXJ and NVXJ are constructed the same except for the following :
Mark No. Symbol and Description Part No. Remarks
XR-A770 XR-A770
/MYXJ /NVXJ
NSP 26 Name Label Not used XAL3012
41 Caution Label HE PRW1233 Not used
42 Caution Label VRW1094 Not used
43 Caution Label Not used PRW1018

8
XR-A770
2.4 FRONT PANEL SECTION
17
17
26
32
23
15
18
19
21
21
33
30
31
27
13
14
16
25
24 35
2
1
6
717
8
36
34(2/2)
34(1/2)
37
20
28
44 43
45
17
6
38
Refer to
"2.7 MECHANISM UNIT".
40
12
17
17
10
46 9
17
3
5
42
A
A

9
XR-A770
•FRONT PANEL SECTION PARTS LIST
Mark No. Description Part No. Mark No. Description Part No.
1 DISPLAY Assy XWZ3123
2 CD SW LED Assy XWZ3131
3 SUB DISPLAY Assy XWZ3112
4 • • • • •
NSP 5 Cord With Plug DE007VE0
6 Flexible Cable 14P XDD3011
7 Flexible Cable 19P XDD3009
8 Flexible Cable 38P XDD3004
9 Connector Assy 3P XDE3013
10 Connector Assy 5P XDE3014
11 • • • • •
12 Mechanism Unit XYM3003
13 Door Spring L XBH3001
14 Door Spring R XBH3002
15 Latch Spring L ABH7130
16 Latch Spring R ABH7131
17 Screw BPZ30P100FZK
18 Latch Mold L XMR3001
19 Latch Mold R XMR3002
NSP 20 Jog Lens XAK3025
21 Damper Assy AXA7052
22 • • • • •
NSP 23 Front Panel Assy XXG3016
24 Function Button XZN3020
25 CD Button XZN3018
26 CD Lens XZN3037
27 Deck Lens L XZN3035
28 Deck Lens R XZN3036
29 • • • • •
30 Door Pocket L XZN3013
31 Door Pocket R XZN3015
32 Front Panel A XZN3011
33 Sub Panel A XZN3041
34 Power Button XZN3022
35 Play Button XZN3024
36 S.C. Button XZN3025
37 TIMER Button XZN3029
38 Sub Buttun XAD3012
39 • • • • •
40 Diffusion Sheet XAK3035
41 • • • • •
42 Button Lens XAK3043
NSP 43 Front Panel Assy B XXG3026
44 Sub Panel B XZN3052
45 Front Panel B XZN3050
46 Binder ZCA-SKB90BK

10
XR-A770
2.5 $M MECHANISM CD
8
7
14
13
12 26
15
21 25
22
24
23
11
5
2
1
10
16
18
29
29 6
17
19
Refer to "2.6 SERVO MECHANISM ASSY".
9
3
29
29
29
27
28
29
29
29
29
30

11
XR-A770
•$M MECHANISM CD PARTS LIST
Mark No. Description Part No.
1 MOTOR Assy AWZ8428
NSP 2 SW Assy AWZ8429
3 CD Assy XWZ3141
4 • • • • •
5 Servo Spring ABH7126
6 Belt AEB7072
7 Clamp Magnet AMF7001
8 Yoke ANB7067
9 Mecha Base ANW7125
10 Loading Tray ANW7088
11 Servo Base ANW7089
12 Rotary Tray ANW7113
13 Clamper ANW7091
14 Clamper Holder ANW7092
15 Main Cam ANW7093
16 Gear Pully ANW7094
17 Lock Lever ANW7095
18 Planet Gear ANW7096
19 Actuater ANW7097
20 • • • • •
21 15P F.F.C/30V ADD7038
22 Connector Assy (6P) ADE7010
23 Float Rubber A AEB7063
24 Float Rubber B AEB7066
25 Servo Mechanism Assy AXA7039
26 Screw IPZ30P080FMC
27 Carriage Motor VXM1033
28 Motor Pulley PNW1634
29 Ha Narl GEM1016
30 Cushion Rubber XEB3003
1 Servo Mechanism AXA7039
2 SPINDLE MOTOR Assy AEA7009
3 SLEAD MOTOR Assy AEA7010
4 Gear A AEA7013
5 Gear B AEA7014
6 Screw AEA7015
7 Screw AEA7016
8 Screw AEA7017
9 Screw AEA7018
10 Leaf Switch AEA7011
Mark No. Description Part No.
•SERVO MECHANISM ASSY PARTS LIST
2.6 SERVO MECHANISM ASSY
1
9
9
9
7
4
5
8
6
3
210
9

12
XR-A770
2.7 MECHANISM UNIT
1
10
13
12
Mech. Ι
Mech. ΙΙ
Mech. ΙΙ
Mech. Ι
Mech. ΙΙ
Only
Mech. Ι
Only
Mech. ΙΙ
Only
2
9
4
3
7

13
XR-A770
5
11
8
6
Mark No. Description Part No.
•MECHANISM UNIT PARTS LIST
1 Plate HD BLK (Mech. Ι) F513-819
2 Plate HD BLK (Mech. ΙΙ) F513-811
3 Motor Main BLK (Mech. ΙΙ only) F525-324
4 PCB Control BLK F567-621
5 Clutch Assy BLK F522-037
6 Main Belt FF17G-31
7 Joint Belt 113 (Mech. ΙΙ only) FF19D-21
8 Clutch Assy BLK F522-045
9 Roller Pinch BLK R F514-129
10 Roller Pinch BLK L F514-130
11 F/R Belt FF18W-12
12 Plate Base BLK F512-127
13 Plate Base BLK F512-128

XR-A770
14
A
B
C
D
1234
1234
1/3
AF ASSY
(XWZ3120)
DISPLAY ASSY
(XWZ3123)
SERVO MECHANISM ASSY (AXA7039)
E
CD ASSY(XWZ3141)
CN8001 CN8002
DECK MECHA
B
I
SUB DISPLAY ASSY
(XWZ3112)
K
FM/AM
TUNER MODULE
(AXQ7068)
A
E
3/3
E
3. SCHEMATIC DIAGRAM
3.1 OVERALL WIRING DIAGRAM

XR-A770
15
A
B
C
D
5678
5678
CN8003
REAR AMP ASSY
(XWZ3122)
L
SECONDARY
ASSY
(XWZ3121)
F
CD SW LED
ASSY
(XWZ3131)
J
PRIMARY
ASSY
(XWZ3152)
G
SUB TRANS
ASSY
(XWZ3139)
H
MOTOR
ASSY
(AWZ8428)
CSW ASSY
(AWZ8429)
D
Note : When ordering service parts, be sure to refer to "EXPLODED VIEWS and PARTS LIST" or "PCB PARTS LIST".

XR-A770
16
A
B
C
D
1234
1234
FM/AM TUNER MODULE
(AXQ7068)
A
RF AMP
MIX AMP
BUFFER
IF AMP
PLL
FM +B SW
AM RF TUNING BLOCK
OSC
3.2 FM/AM TUNER MODULE
A

XR-A770
17
A
B
C
D
5678
5678
2/3
E
CN3051
AF AMP
REGULATOR
AF AMP
A

XR-A770
18
A
B
C
D
1234
1234
BCD ASSY
SERVO MECHANISM ASSY AXA7039
CMOTOR ASSY
(AWZ8428)
J8502
D20PWW0405E
56k
R8123
CARRIAGE MOTOR
(XWZ3141)
3.3 CD, MOTOR and SW ASSEMBLIES
B C

XR-A770
19
A
B
C
D
5678
5678
D
SW ASSY
(AWZ8429)
C8371 100/10
L8371 47µH
J8502
2
1CN8005- Pin 1 :
PLAY MODE (RF)
VREF:CN8005- Pin3
VREF
1.8Vp-p
CN8005- Pin 2 :
TEST MODE,
Tracking Open(TRER)
1.0Vp-p
H : 500nsec/div
H : 5msec/div
VREF
1
2
Note: The encircled numbers
denote measuring point in the
schematic diagram.
2/3E
CN1052
C8257
0.1
2SD1858X 2SD1858X
2SB1237X 2SB1237X
0.047
C8256 0.1
C8255 0.1
YB
YB
C8308
1000p
C8307
1000p
0.047
B D

XR-A770
20
A
B
C
D
1234
1234
3.4 AF ASSY (1/3)
1/3
AF ASSY
(XWZ3120)
: DECK PB SIGNAL ROUTE
E
(PB)
: DECK REC SIGNAL ROUTE
(REC)
(PB)
(PB)
(PB)
(PB)
(PB)
(REC)
(REC)
(REC) (REC)
(REC)
(REC)
(REC)
(PB)
22k
22k
0.022
C2323
0.022
33k
33k
220k
220k
0.01
47p
47p
47p
47p
1/3
E