Yamaha NS-P240 User manual

SERVICE MANUAL
This manual has been provided for the use of authorized YAMAHA Retailers and their service personnel.
It has been assumed that basic service procedures inherent to the industry, and more specifically YAMAHA Products, are already
known and understood by the users, and have therefore not been restated.
WARNING: Failure to follow appropriate service and safety procedures when servicing this product may result in personal
injury, destruction of expensive components, and failure of the product to perform as specified. For these reasons,
we advise all YAMAHA product owners that any service required should be performed by an authorized YAMAHA
Retailer or the appointed service representative.
IMPORTANT: The presentation or sale of this manual to any individual or firm does not constitute authorization, certification or
recognition of any applicable technical capabilities, or establish a principle-agent relationship of any form.
The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research, engineering, and service
departments of YAMAHA are continually striving to improve YAMAHA products. Modifications are, therefore, inevitable and
specifications are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the
distributor's Service Division.
WARNING: Static discharges can destroy expensive components. Discharge any static electricity your body may have
accumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss).
IMPORTANT: Turn the unit OFF during disassembly and part replacement. Recheck all work before you apply power to the unit.
IMPORTANT NOTICE
100880
SERVICE MANUAL
NS-P240/NS-P246
HOME THEATER SOUND SPEAKER SYSTEM
NS-P240/NS-P246 is composed of NX-S120, NX-C120 and SW-P240.
NS-P240/NS-P246は、NX-S120・NX-C120・SW-P240で構成されています。
SW-P240 BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . .8
SW-P240 PRINTED CIRCUIT BOARD . . . . . . . . . . . .9
SW-P240 SCHEMATIC DIAGRAM . . . . . . . . . . . . . .10
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11–15
■ CONTENTS
TO SERVICE PERSONNEL . . . . . . . . . . . . . . . . . . . .2
FRONT PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
REAR PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–4
SPECIFICATIONS / 参考仕様 .................. 4–6
SW-P240 INTERNAL VIEW . . . . . . . . . . . . . . . . . . . .6
SW-P240 DISASSEMBLY PROCEDURES /
SW-P240分解手順............................. 7
NS-P240
NS-P246

NS-P240/NS-P246
2
NS-P240
NS-P246
■ TO SERVICE PERSONNEL
1. Critical Components Information
Components having special characteristics are marked Z
and must be replaced with parts having specifications equal
to those originally installed.
2. Leakage Current Measurement (For 120V Models Only)
When service has been completed, it is imperative to verify
that all exposed conductive surfaces are properly insulated
from supply circuits.
●Meter impedance should be equivalent to 1500 ohm shunted
by 0.15µF.
AC LEAKAGE
TESTER OR
EQUIVALENT
EQUIPMENT
UNDER TEST
INSULATING
TABLE
WALL
OUTLET
●Leakage current must not exceed 0.5mA.
●Be sure to test for leakage with the AC plug in both
polarities.
WARNING: CHEMICAL CONTENT NOTICE!
The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and/or
plastic (where applicable) components may also contain traces of chemicals found by the California Health and
Welfare Agency (and possibly other entities) to cause cancer and/or birth defects or other reproductive harm.
DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH FOR
ANY REASON WHATSOEVER!
Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes
or expose eyes to solder/flux vapor!
If you come in contact with solder or components located inside the enclosure of this product, wash your hands
before handling food.
▼ SW-P240
■FRONT PANELS
▼ NX-C120 ▼ NX-S120
x 4 (for NS-P240)
x 5 (for NS-P246)

NS-P240/NS-P246
NS-P240
NS-P246
3
■REAR PANELS
▼ SW-P240 (U, C models) ▼ SW-P240 (T model)▼ SW-P240 (R, L models)
KTL SU09109-
▼ SW-P240 (K model) ▼ SW-P240 (B, G models)▼ SW-P240 (A model)

NS-P240/NS-P246
4
NS-P240
NS-P246
●NX-S120
Type /  . . . . . . . . . . . . Full Range Acoustic Suspension
Magnetic Shielding Type
Driver / 
. 5 cm (2”) Cone Magnetic Shielding Type x 2
Frequency Response / 
 100 Hz to 25 kHz
Impedance /  . . . . . . . . . . . . . . . 6 ohms
Nominal Input /  30 W
Maximum Input /   100 W
Sensitivity /  . . . . . . . . 86 dB/2.83 V/m
InputTerminal /  . . . . . . . . . . . . . . Push Type
Dimensions (W x H x D) / 
. . . . . . . . . . . . . 72 mm x 170 mm x 108 mm
(2-13/16” x 6-11/16” x 4-1/4”)
Weight /  . . . . . . . . . . . . . . . . . . . . . . 0.9 kg (2 lbs.)
Finish /  . . . . . . . . . . . . . . . . . . . . . . . Silver color
Black color
Appropriate Speaker Stand /  . . . SPS-80
Appropriate Speaker Bracket /  . . . SPM-8S
●NX-C120
Type /  . . . . . . . . . . . . Full Range Acoustic Suspension
Magnetic Shielding Type
Driver / 
. 5 cm (2”) Cone Magnetic Shielding Type x 2
Frequency Response / 
 100 Hz to 25 kHz
Impedance /  . . . . . . . . . . . . . . . 6 ohms
Nominal Input /  30 W
Maximum Input /   100 W
Sensitivity /  . . . . . . . . 86 dB/2.83 V/m
InputTerminal /  . . . . . . . . . . . . . . Push Type
Dimensions (W x H x D) / 
. . . . . . . . . . . . . 300 mm x 72 mm x 105 mm
(11-13/16” x 2-13/16” x 4-1/8”)
Weight /  . . . . . . . . . . . . . . . . . 1.1 kg (2 lbs.6 oz.)
Finish /  . . . . . . . . . . . . . . . . . . . . . . . Silver color
Black color
■SPECIFICATIONS/参考仕様
▼ SW-P240 (J model)
NX-S120
IMPEDANCE
NOMINAL
MAXIMUM INPUT
INPUT
6 OHMS
30 WATTS
100 WATTS
NX-C120
IMPEDANCE
NOMINAL
MAXIMUM INPUT
INPUT
6 OHMS
30 WATTS
100 WATTS
▼ NX-S120
▼ NX-C120

NS-P240/NS-P246
NS-P240
NS-P246
5
U ....... USA model
C ....... Canadian model
R ....... General model
T ....... Chinese model
K ....... Korean model
A ....... Australian model
B ....... British model
G ....... European model
L ....... Singapore model
J ....... Japanese model
●SW-P240
Type /  . . . . . AdvancedYamaha Active Servo Technology
Output Power /   50 W (100 Hz, 5 ohms, 10 %THD)
Dynamic Power /   100 W, 5 ohms
Input Impedance / 
INPUT (PJ) . . . . . . . . . . . . . . . . . . . . . . . . 12 k-ohms
Frequency Response /   30 Hz to 200 Hz
Driver /   16 cm (6-1/2”) cone
Magnetic Shielding Type
Input Section / 
INPUT . . . . . . . . . . . . . . . . . . . . . . . . . RCA Pin Jack
Power Supply / 
U, C models . . . . . . . . . . . . . . . . . . . AC 120V, 60 Hz
R, T, K, L models . . AC 110-120/220-240V, 50/60 Hz
A model . . . . . . . . . . . . . . . . . . . . . . AC 240 V, 50 Hz
B, G models . . . . . . . . . . . . . . . . . . . AC 230 V, 50 Hz
J model . . . . . . . . . . . . . . . . . . . . AC 100V, 50/60 Hz
Power Consumption / 
U, C, A, B, G, R, T, K, L models . . . . . . . . . . . . . 40 W
J model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 W
Dimensions (W x H x D) / 
. . . . . . . . . . . . 200 mm x 365 mm x 390 mm
(7-7/8” x 14-7/20” x 15-5/16”)
Weight /  . . . . . . . . . . . . . . . . 8.4 kg (18 lbs.8 oz.)
Finish / 
Silver color . . . . . . U, C, R, T, K, A, B, G, L, J models
Black color . . . . . . . . . . . . . . . . U, C, R, A, G models
●Accessories / 
NS-P240 . . . . . . . . . . . . . . . Subwoofer Cable (5m) x 1
Nonskid Pad x 4 (for subwoofer)
Speaker Cable (15 m) x 2
Speaker Cable (4 m) x 3
Nonskid Pads x 16
Mounting Bracket x 4, Screws x 4
Fasteners x 2
NS-P246 . . . . . . . . . . . . . . . Subwoofer Cable (5m) x 1
Nonskid Pad x 4 (for subwoofer)
Speaker Cable (15 m) x 3
Speaker Cable (4 m) x 3
Nonskid Pads x 20
Mounting Bracket x 5, Screws x 5
Fasteners x 2
* Specifications subject to change without notice.

NS-P240/NS-P246
6
NS-P240
NS-P246
■SW-P240 INTERNAL VIEW
wq
re
qMAIN (2) P.C.B.
wMAIN (1) P.C.B.
eMAIN (3) P.C.B.
rPOWER TRANSFORMER
Unit : mm (inch)
300 (11-13/16") 105 (4-1/8")
72 (2-13/16")
72 (2-13/16") 108 (4-1/4")
170 (6-11/16")
● NX-S120
● NX-C120
200 (7-7/8") 390 (15-5/16")
365 (14-3/8")
DIMENSIONS/寸法図
● SW-P240

NS-P240/NS-P246
NS-P240
NS-P246
7
1. Removal of Front Grille
The Front Grille is fixed to the cabinet with dowels
at 6 locations. As a screwdriver (for slotted head
screw) is used for removal, use special care not to
cause damage to the cabinet.
a. Using the screwdriver inserted in the gap between
the Front Grille and the cabinet (bottom side first),
push up the Front Grille.
b. Remove the Front Grille by lifting it up.
* When installing the Front Grille, apply quick-drying
bond to the dowels and then fit them into dowel holes
for secure installation. (The Front Grille will come off
easily if its dowels are fitted into dowel holes only.)
2. Removal of Rear Panel
Remove 14 screws ( q) in Fig. 2.
* Arrow marks ( ) are printed to identify the screws to
be removed.
* When assembling the Rear Panel, check to ensure that
the packing is not damaged so as to prevent air leakage
from occurring.
■SW-P240 DISASSEMBLY PROCEDURES/SW-P240分解手順
(Remove parts in disassembly order as numbered.) (番号順に部品を取り外してださい。）
1.フロントグリルの外し方


a. 底側からマイナスドライバー等を差し込み、フロントグ
リルを押し上げます。（Fig.1）
b. 徐々に上面ヘマイナスドライバー等で押し上げて、フロ
ントグリルを外します。
 


2.リアパネルの外し方
qのネジ14本を外し、リアパネルを取り出します。
（Fig.2）
 
 

Fig. 1 Fig. 2

q



NS-P240/NS-P246
8
NS-P240
NS-P246
■ SW-P240 BLOCK DIAGRAM
IC1B IC7A
VR1
VOLUME
L.P.F.
6dB/oct H.P.F. 12dB/oct
L.P.F.
12dB/oct
6
575
7IC7B
IC4
IC3
A.N.I.C
LIMITER
RY1
312
IC2
Q9
D14, 15, 16
Q3, 4, 5, 8
D9, 10, 11, 12
1
10
–B
+B
9
8
0.1
PROTECTION
+12
+B
–B
–12
REGULATOR
POWER SUPPLY
D3
Q1, D6
Q2, D7
F2
POWER
SW2
SPEAKER
INPUT
+
–
POWER
AMP

ABCDEFGH
1
2
3
4
5
6
NS-P240/NS-P246
9
■SW-P240 PRINTED CIRCUIT BOARD
INPUT
VOLUME
POWER
POWER CABLE
WH RE
SPEAKER
P.C.B. MAIN (1)
P.C.B. MAIN (2)P.C.B. MAIN (3)
R, T, K, L models
U, C, A, B, G, J models
SW1 (R,T,K,L)
AC110~220V
AC220~240V
BE
BE
WH
WH
SW-P240

ABCDEFGH
1
2
3
4
5
6
NS-P240/NS-P246
10
POWER AMP
PROTECTION
LIMITTER
MAIN (2)
MAIN (3)
MAIN (1)
POWER
SW2
SY16-52-4
(U99S2)/T
15K SLR-56MG
5KA
0
00
0
000
00
0
0
00
00
0
0
0.2
-0.7 -0.7
1.1 1.4 3.1
0 0 0 0
0.2
0
0
-33.9
11.6
1.2
-1.2
-34.4
34.3
0.5
11.6
34.2
-34.4
11.6
34.2
11.6
-11.6
-11.6
-11.6
0
00
00
0
0
11.6
-11.6
AC25.2
AC25.2
■SW-P240 SCHEMATIC DIAGRAM
IC1, 2, 7 : KIA4558P
Dual OP-Amp
–+
OUT 1
–IN 1
–V CC
+V CC
OUT 2
1
2
3
45
+IN 1 –IN 2
+IN 2
–+
6
7
8
IC4 : STK404-050
Power Amp
12345678910
R1 R4
R5
C1 C2
D1
TR3
TR5
R3 R6
TR4
SUB
R2
TR1 TR2
TR6
TR7
TR8
IC3 : TA7317P
Protector
16
2
3
8
7 4
9
Muting
circuit Constant voltage
power supply circuit
Schmidt
circuit
Power supply
ON/OFF
detecting circuit
Discharging
circuit
5
Substrate
Overcurrent
detecting circuit OR circuit
Current voltage
detecting circuit
GND
Relay drive
circuit
*All voltages are measured with a 10M Ω /V DC electronic volt meter.
* Components having special characteristics are marked Z and
must be replaced with parts having specifications equal to those
originally installed.
* Schematic diagram is subject to change without notice.
* 電圧は、内部抵抗10MΩの電圧計で測定したものです。
*Z印のある部品は、安全性確保部品を示しています。部品の交換が必要な場合、パー
ツリストに記載されている部品を使用してください。
* 本回路図は、標準回路図です。改良のため予告なく変更することがございます。