Pioneer GM-X944 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 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 2000 K-ZZA. MAR. 2000 Printed in Japan
ORDER NO.
CRT2483
BRIDGEABLE FOUR-CHANNEL POWER AMPLIFIER
GM-X944 X1R/UC,EW,ES
Service
Manual
CONTENTS
1. SAFETY INFORMATION............................................2
2. EXPLODED VIEWS AND PARTS LIST ......................2
3. SCHEMATIC DIAGRAM.............................................6
4. PCB CONNECTION DIAGRAM................................12
5. ELECTRICAL PARTS LIST........................................18
6. ADJUSTMENT .........................................................24
7. GENERAL INFORMATION.......................................25
7.1 DISASSEMBLY ..................................................25
8. OPERATIONS AND SPECIFICATIONS ....................26
GM-X944/X1R/UC

2
GM-X944
2. EXPLODED VIEWS AND PARTS LIST
2.1 PACKING
1. SAFETY INFORMATION
-GM-X944/X1R/UC
CAUTION
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.
WARNING
This product contains lead in solder and certain electrical parts contain chemicals which are known to the state of
California to cause cancer, birth defects or other reproductive harm.
Health & Safety Code Section 25249.6 - Proposition 65

3
GM-X944
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
Model Part No. Language
GM-X944/X1R/UC HRD0138 English, French
GM-X944/X1R/EW HRD0139 English, Spanish, German,
French, Italian, Dutch
GM-X944/X1R/ES HRD0140 English, Spanish
HRD0141 Portuguese(B), Arabic
-PACKING SECTION PARTS LIST
Part No.
Mark No. Description GM-X944/X1R/UC GM-X944/X1R/EW GM-X944/X1R/ES
1 •••••
2 Screw BYC40P180FZK BYC40P180FZK BYC40P180FZK
3 Polyethylene Bag HEG0011 HEG0011 HEG0011
4 Polyethylene Bag HEG0021 HEG0021 HEG0021
5 Carton HHG0248 HHG0249 HHG0250
6 Contain Box HHL0248 HHL0249 HHL0250
7 Protector HHP0079 HHP0079 HHP0079
8-1 Owner’s Manual HRD0138 HRD0139 HRD0140
8-2 Owner’s Manual Not used Not used HRD0141
* 8-3 Warranty Card Not used HRY1157 Not used
* 8-4 Card ARY1048 Not used Not used
* 8-5 PRC HRY0012 Not used Not used
9 Cover HNS0101 HNS0101 HNS0101
10 Protector HHP0096 HHP0096 HHP0096

4
GM-X944
2.2 EXTERIOR

5
GM-X944
(1) EXTERIOR SECTION PARTS LIST
Mark No. Description Part No. Mark No. Description Part No.
1 Screw BSZ30P050FZK
2 Screw(M3x12) CBA1323
3 Screw(M3x5) HBA0006
4 Screw(M3x8) HBA0011
5 Screw(M2.6x6) HBA0012
6 Screw(M3x16) HBA0020
7 Panel See Contrast table(2)
8 Case See Contrast table(2)
9 Holder HNC0078
10 Heat Sink See Contrast table(2)
11 Plate HNS0077
12 Plate HNS0080
13 Cover HNS0101
14 Spacer HNV0016
15 Amp Unit See Contrast table(2)
16 Screw BBZ30P060FMC
17 Screw(M3x14) CBA1382
18 Terminal(CN905) CKF1059
19 Plug(CN906) CKS1035
20 Connector(CN101) CKS3146
21 Connector(CN103) CKS3146
22 Fuse HEK0030
23 Pin Jack(CN852) HKB0002
24 Pin Jack(CN851) HKB0006
25 Fuse Holder HKE0012
26 Terminal(CN901) HKE0020
27 Connector(CN301) HKE0030
28 Clip HNC0054
29 Holder HNC0076
30 Bar HNR0124
31 Heat Sink HNR0148
32 Heat Sink HNR0149
33 Network Unit See Contrast table(2)
34 Connector(CN102) CKS3145
35 Connector(CN104) CKS3145
36 Clip HNC0054
37 Screw PPZ30P100SAD
38 Light Pipe Unit HXA0322
39 Fan Motor HXM0001
40 Screw PPZ30P100FZK
41 Thermistor(TH901, 902) CCX1013
42 Thermistor(TH904) CCX1027
43 FET 94-4981
(Q361, 362, 363, 364, 365, 366, 367, 368)
44 FET STP50NE08
(Q905, 906, 911, 912, 913, 914)
45 Transistor(Q907) 2SD2395
46 Diode(D910) FML22R
47 Transistor(Q908) 2SB1566
48 Diode(D907) FML22S
49 FET 94-4980
(Q353, 354, 355, 356, 357, 358, 359, 360)
50 Screw BBZ30P140FMC
51 Screw BBZ30P060FMC
(2) CONTRAST TABLE
GM-X944/X1R/UC, EW and ES are constructed the same except for the following:
Part No.
Mark No. Description GM-X944/X1R/UC GM-X944/X1R/EW GM-X944/X1R/ES
7 Panel HNB0121 HNB0104 HNB0121
8 Case HNB0122 HNB0106 HNB0122
10 Heat Sink HNR0160 HNR0165 HNR0160
15 Amp Unit HWH0134 HWH0123 HWH0135
33 Network Unit HWG0020 HWG0016 HWG0021

NETWORK PCB(A)
NETWORK PCB(B)
AMP UNIT
CN851
CN851
CN852
CN852
CN851
CN851
CN101 CN102
CN102-2 CN101-2
CN103 CN104
CN104-2 CN103-2
ISOLATOR
GAIN=1
ISOLATOR
GAIN=1
RCA OUT
GAIN=1
HP/LP FILTER
12dB/OCTAVE
BP FILTER
LOW-X TO HIGH-X
HP/LP FILTER
12dB/OCTAVE
POWER SUPPLY
HIGH XOVER
3k-9kHz
LOW XOVER
40-120Hz
HIGH XOVER
3k-9kHz
LOW XOVER
40-120Hz NETWORK UNIT
Consists of
•NETWORK PCB
•NETWORK PCB
FAN MOTOR HXM0001
6
GM-X944
A
1234
B
C
D
1234
A-a A-b
A-a
A-a
A-b
A-b
A-b
A-b
A-a
A-a
Large size
SCH diagram
Guide page
Detailed page
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-a
A B C
C
B
A

CN301
CN301
CN903
CN904
CN902
CN901
AMP
GAIN=8.5-33dB
AMP
GAIN=8.5-33dB
IT
CB(A)
CB(B)
GM-X944/X1R/EW, ES
CN906
220
HZS12L(A3)
7
GM-X944
5678
A
B
C
D
5678
A-b
A

8
GM-X944
A
1234
B
C
D
1234
NETWORK PCB(A)
AMP UNIT
CN851 CN851 CN852
CN851 CN851
CN101
CN102
CN102-2
CN101-2
CN103
CN104
CN104-2
CN103-2
ISOLATOR GAIN=1 ISOLATOR GAIN=1
RCA OUT GAIN=1
HP/LP FILTER 12dB/OCTAVE
BP FILTER LOW-X TO HIGH-X
HIGH XOVER 3k-9kHz LOW XOVER 40-120Hz NETWORK UNIT
Consists of •NETWORK PCB(A) •NETWORK PCB(B)
A-a
A-a A-b
1
B C
B
A

9
GM-X944
5678
A
B
C
D
5678
NETWORK PCB(B)
CN852
HP/LP FILTER 12dB/OCTAVE
POWER SUPPLY
HIGH XOVER 3k-9kHz LOW XOVER 40-120Hz
G
CN906
FAN MOTOR
HXM0001
A-a
A-a A-b
2 3
C
C

10
GM-X944
A
1234
B
C
D
1234
CN301 CN301
AMP GAIN=8.5-33dB AMP GAIN=8.5-33dB
T
B(A) B(B)
A-a A-b
A-b
1