Sony STR-NX300 User manual

SERVICE MANUAL
MICROFILM
Amplifier section
The following measured at AC 120/220/240 V,
50/60 Hz
Front Speaker:
DIN power output (rated) 95 + 95 watts
(6 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
120 + 120 watts
(6 ohms at 1 kHz,
10% THD)
Centre Speaker:
DIN power output (rated) 25 watts
(8 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
35 watts
(8 ohms at 1 kHz,
10% THD)
Rear Speaker:
DIN power output (rated) 25 + 25 watts
(8 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
35 + 35 watts
(8 ohms at 1 kHz,
10% THD)
Inputs
VIDEO IN: voltage 250 mV,
(phono jacks) impedance 47 kilohms
MD IN: voltage 450 mV,
(phono jacks) impedance 47 kilohms
DVD INPUT:
FRONT IN: voltage 450 mV,
(phono jacks) impedance 47 kilohms
REAR IN: voltage 450 mV,
(phono jacks) impedance 47 kilohms
CENTER IN: voltage 450 mV,
(phono jacks) impedance 47 kilohms
WOOFER IN: voltage 450 mV,
(phono jacks) impedance 47 kilohms
MIC1/2: sensitivity 1 mV,
(mini jack) impedance 10 kilohms
Outputs
MD OUT: voltage 250 mV
(phono jacks) impedance 1 kilohms
VIDEO OUT: max. output level 1 Vp-p,
(phono jack) unbalanced,
Sync negative,
load impedance 75 ohms
S-VIDEO OUT: Y: 1 Vp-p, unbalanced,
(4-pin/mini-DIN jack) Sync negative,
C: 0.286 Vp-p,
load impedance 75 ohms
PHONES: accepts headphones of 8
(stereo mini jack) ohms or more
FRONT SPEAKER: accepts impedance of 6 to
16 ohms
REAR SPEAKER: accepts impedance of 8 to
16 ohms
CENTER SPEAKER: accepts impedance of 8 to
16 ohms
SUPER WOOFER: Voltage 1 V, impedance
1 kilohms
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 MHz
Aerial FM lead aerial
Aerial terminals 75 ohm unbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range
2 Band type: 531 – 1,602 kHz
(with the interval set at
9 kHz)
530 – 1,710 kHz
(with the interval set at
10 kHz)
3 Band type:
MW: 531 – 1,602 kHz
(with the interval set at
9 kHz)
530 – 1,710 kHz
(with the interval set at
10 kHz)
SW: 5.95 – 17.90 MHz
(with the interval set at
5 kHz)
Aerial AM loop aerial
Aerial terminals External aerial terminal
Intermediate frequency 450 kHz
TUNER/AMPLIFIER
E Model
Chinese Model
SPECIFICATIONS
STR-NX300
• STR-NX300 is the Tuner and Amplifier section in MHC-NX300AV.
• STR-NX300 is almost the same as STR-NX3 Singapore model.
The difference portion and the difference parts from STR-NX3 Singapore model are de-
scribed in this service manual.
Please refer to STR-NX1/NX3 service manual (9-928-980-S) previously issued for other
information.
– Continued on next page –

2
PART No.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED
LINE WITH MARK 0ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.
1. SERVICING NOTES
• MODEL IDENTIFICATION (Page 3)
– Rear Panel –
MODEL PART No.
Malaysia, Singapore and Hong Kong models 4-221-391-5[]
Thai and Chinese models 4-221-391-7[]
General
Power requirements
Thai and Chinese models: 220 V AC, 50/60 Hz
Other models:
120 V, 220 V or
230 – 240 V
AC, 50/60 Hz
Adjustable with voltage
selector
Power consumption 300 watts
Dimensions (w/h/d) Approx. 225 x 202 x 356
mm
Mass Approx. 8.1 kg
Design and specifications are subject to change
without notice.

3
2. GENERAL
• LOCATION OF CONTROLS (Page 4)
– Front Panel –
– Rear Panel –
1DISPLAY button
2?/1button and indicator
3POWER SAVE/DEMO (STANDBY) button
4– mbutton
5+ Mbutton
6FILE SELECT button
7VIDEO/DVD button
8EDIT button
9MD button
0REPEAT button
qa TAPE button
qs PLAY MODE button
qd CD button
qf DBFB button
qg TUNER button
qh DSP button
qj TUNER BAND button
qk STEREO/MONO button
ql TUNER MEMORY button
w; KARAOKE PON button
wa GROOVE button and indicator
ws ECHO LEVEL knob
wd MIC LEVEL knob
wf MIC 1 jack
wg MIC 2 jack
wh PHONES jack
wj Remote sensor
wk Jog dial
wl ENTER button and indicator
e; DVD 5.1CH button and indicator
ea PRO LOGIC button and indicator
es VOLUME knob
1AM ANTENNA terminals
2FM ANTENNA terminal
3SYSTEM CONTROL connector
4VIDEO (AUDIO) IN jacks
5MD IN jacks
6MD OUT jacks
7DVD 5.1CH INPUT jacks
8SUPER WOOFER OUT jack
9VOLTAGE SELECTOR switch
(Malaysia, Singapore and Hong Kong models)
q; FRONT SPEAKER terminals
qa REAR SPEAKER terminals
qs CENTER SPEAKER terminals
–
+
–+
M
l
m
>
1
2
3
4
5
wh wj wk wl e; ea
608 qs qf qh
79qa qd qg
qk
ql
wa
w;
ws
wd
wf
wg
es
qj
3
4
5
6
7
8
3
4
5
6
7
8
0qa qs 0qa qs
99
2
12 1

4
10
1 Press CLOCK/TIMER.
The hour indication flashes.
2 Press Vor vrepeatedly to set the
hour.
3 Press ENTER.
The minute indication flashes.
4 Press Vor vrepeatedly to set the
minute.
5 Press ENTER.
The clock starts working.
Tips
• If you make a mistake, start over from step 1.
• Setting the time deactivates the demo mode.
If you want to display the demo mode, press
DEMO (STANDBY) when the power is off.
To change the time
The previous explanation shows how to set
the time while the power is off. To change the
time while the power is on, do the following:
1Press CLOCK/TIMER.
2Press Vor vrepeatedly to select the SET
CLOCK.
3Press ENTER.
4Perform steps 2 through 5 above.
Note
The clock settings are cancelled when you
disconnect the mains lead or if a power failure
occurs.
You must set the time before using the timer
functions.
Step 3: Setting the
time
2,4 3,5
1
V
v
bB
(Page 5)

5
3. DIAGRAMS
3-1. IC PIN FUNCTION DESCRIPTION (Page 24, 25)
(STR-NX1/NX3)
•MAIN BOARD IC501 M30622MA-A12FP (SYSTEM CONTROLLER )
Pin No. Pin Name I/O Description
93 KEY1 I
Key input terminal (A/D input)
S615 to S617, S619 to S624 (TUNER BAND, STEREO/MONO, TUNER MEMORY,
GROOVE, + M, – m, ENTER, DVD 5.1CH, PRO LOGIC) keys input
(S623 DVD 5.1CH, S624 PRO LOGIC keys: used for the STR-NX3 only)
(STR-NX300)
•MAIN BOARD IC501 M30622MA-A29FP (SYSTEM CONTROLLER )
Pin No. Pin Name I/O Description
93 KEY1 I Key input terminal (A/D input)
S615 to S624 (TUNER BAND, STEREO/MONO, TUNER MEMORY, KARAOKE PON,
GROOVE, + M, – m, ENTER, DVD 5.1CH, PRO LOGIC) keys input

6
3-2. PRINTED WIRING BOARD – MAIN Board –
STR-NX300
Page STR-NX1/NX3 STR-NX300
15
!: Difference portion.
• Abbreviation
CH : Chinese model
HK : Hong Kong model
MY : Malaysia model
SP : Singapore model
TH :Thai model
Location C – D, 6 – 8
(MY, SP, HK, CH)
Location D – G, 2 – 5
(TH, CH)
R540
R541
CN191
10 1
(FOR TEST)
(CH)
R526
R529
(CH)
(CH) (CH)
(CH)
#$
%
$
@
#

77
STR-NX300
3-3. SCHEMATIC DIAGRAM – MAIN Board (2/3) – (Page 13)
!: Difference portion.
• Abbreviation
CH : Chinese model
HK : Hong Kong model
MY : Malaysia model
SP : Singapore model
TH :Thai model
$
^
!
#
#

88
STR-NX300
3-4. SCHEMATIC DIAGRAM – PA Board –
!: Difference portion.
Page STR-NX1/NX3 STR-NX300
3-5. PRINTED WIRING BOARD – PANEL Board –
!: Difference portion.
Location A – D, 9 – 12
19 !
#
Page STR-NX1/NX3 STR-NX300
Location D – E, 1
20
Location F – G, 1 – 4
KARAOKE
PON
S618
C704
R701
R702 C723
R711
R715
C727
C721
R713
R714
C722 C724 C725 C726
R717
R721
C728
R716
C731
C729
16 9
18
IC702
C732
R718
C734
D701
C735
R712
@
#
^
@

99
STR-NX300
3-6. SCHEMATIC DIAGRAM – PANEL Board – (Page 21)
!: Difference portion.
IC702 M65850FP
OSCILLATOR
1/2 VCC
AUTO
RESET
LPF1
MAIN
CONTROL
A/D
20KBIT
SRAM
LPF2
D/A
12 3 45 6 7
891014 13 12 11
CLOCK
RESET
MO
MI
D1 DO0
DO1
VCC CLOCK REF OP2IN OP2OUT LPF2IN LPF2OUT
LPF1IN
LPF1OUT
OP1OUT
OP1IN
CC1 CC2
GND
^
%
!
$
!

1010
STR-NX300
(MY, SP, HK)
(TH, CH)
3-7. PRINTED WIRING BOARD AND SCHEMATIC DIAGRAM –TRANS Board –
!: Difference portion.
Page STR-NX1/NX3 STR-NX300
4. EXPLODED VIEWS
• Abbreviation
CH : Chinese model
HK : Hong Kong model
MY : Malaysia model
SP : Singapore model
TH :Thai model
The components identified by mark 0or dotted
line with mark 0are critical for safety.
Replaceonly with partnumber specified.
Page STR-NX1/NX3 STR-NX300
Ref. No. Part No. Description Remark
3 X-4952-296-1 PANEL ASSY, BACK (MY, SP, HK)
3 X-4952-356-1 PANEL ASSY, BACK (CH, TH)
4 1-751-688-11 WIRE (FLAT TYPE) (13CORE) (TH)
4 1-733-011-11 WIRE (FLAT TYPE) (15CORE)
(MY, SP, HK)
6 1-233-545-11 TUNER PACK (FM/MW/SW) (TH)
6 1-233-546-11 TUNER PACK (FM/MW/SW) (MY, SP, HK)
6 1-693-381-11 TUNER PACK (FM/MW/SW) (CH)
53 X-4952-015-2 PANEL ASSY, FRONT
65 A-4426-655-A PANEL BOARD, COMPLETE
67 1-769-885-11 WIRE (FLAT TYPE) (7CORE)
Ref. No. Part No. Description Remark
26
3 X-4952-296-1 PANEL ASSY, BACK (NX3: MY, SP)
4 1-733-011-11 WIRE (FLAT TYPE) (15CORE)
(AEP, UK, MY, SP, JE)
6 1-233-546-11 TUNER PACK (FM/MW/SW) (MY, SP)
53 X-4951-816-1 PANEL ASSY, FRONT (NX3: E, AUS)
65 A-4426-275-A PANEL BOARD, COMPLETE (NX3: E, AUS)
67 1-769-886-11 WIRE (FLAT TYPE) (7CORE)
65
68
62 68
64
66
67
63
not
supplied
65
68
62 68
64
66
67
63
not
supplied
27
The components identified by
mark 0or dotted line with mark
0are critical for safety.
Replace only with part number
specified.
• Items marked “*” are not stocked since they
are seldom required for routine service. Some
delay should be anticipated when ordering
these items.
• Abbreviation
CH : Chinese model
HK : Hong Kong model
MY : Malaysia model
SP : Singapore model
TH : Thai model
(MY,
S
(
JW953
22
Location A – D, 5 – 7
( MY, SP, HK)
( TH, CH)
@
23
@
#
$
^
#

11
Page STR-NX1/NX3 STR-NX300
Ref. No. Part No. Description Remark
Ref. No. Part No. Description Remark
29
102 A-4426-281-A PA BOARD, COMPLETE (NX3: E, AUS)
0104 1-575-651-11 CORD, POWER (NX: MY, SP)
*105 3-703-244-00 BUSHING (2104), CORD
106 A-4426-277-A MAIN BORD, COMPLETE (NX3: MY, SP)
(US, CND, AEP, UK, KR, MY, SP, AUS)
109 4-221-364-01 CHASSIS
0T951 1-433-996-11 TRANSFORMER, POWER (NX3: E, AUS)
102 A-4428-730-A PA BOARD, COMPLETE
0104 1-777-071-51 CORD, POWER (HK, MY, SP)
0104 1-783-205-11 CORD, POWER (CH)
0104 1-791-901-11 CORD, POWER (TH)
*105 3-703-244-21 BUSHING (2104), CORD (MY, SP, HK, CH)
*105 3-703-571-11 BUSHING (S) (4516), CORD (TH)
106 A-4426-657-A MAIN BORD, COMPLETE (MY, SP, HK)
106 A-4428-007-A MAIN BORD, COMPLETE (CH)
106 A-4428-364-A MAIN BORD, COMPLETE (TH)
0107 1-770-019-11 ADAPTOR, CONVERSION 2P (HK)
109 X-4952-635-1 CHASSIS ASSY
0T951 1-435-279-11 TRANSFORMER, POWER
105 102
#2
#5
supplied
A
105
102
#2
#5 #5
not
supplied
A
The components identified by
mark 0or dotted line with
mark 0are critical for safety.
Replace only with part num-
ber specified.

12
5. ELECTRICAL PARTS LIST
• Items marked “*” are not stocked since they
are seldom required for routine service.
Some delay should be anticipated when order-
ing these items.
The components identified by
mark 0or dotted line with mark
0are critical for safety.
Replace only with part number
specified.
When indicating parts by reference
number, please include the board.
• Abbreviation
CH : Chinese model
HK : Hong Kong model
MY : Malaysia model
SP : Singapore model
TH : Thai model
Page STR-NX1/NX3 STR-NX300
Ref. No. Part No. Description RemarkRef. No. Part No. Description Remark
30
32
35
36
A-4426-277-A MAIN BOARD, COMPLETE (NX3: MY, SP)
*********************
CN121 1-784-776-11 CONNECTOR, FFC 15P
(AEP, UK, MY, SP, JE)
IC501 8-759-597-56 IC M30622MA-A12FP
R582 1-249-407-11 CARBON 150 5% 1/4W
(NX3)
R584 1-249-417-11 CARBON 1K 5% 1/4W
(MY, SP, JE)
A-4426-281-A PA BOARD, COMPLETE (NX3: E, AUS)
*******************
C883 1-127-813-11 ELECT 3300uF 20% 71V
(E, AUS, JE)
C884 1-127-813-11 ELECT 3300uF 20% 71V
(E, AUS, JE)
A-4426-657-A MAIN BOARD, COMPLETE (MY, SP, HK)
A-4428-007-A MAIN BOARD, COMPLETE (CH)
A-4428-364-A MAIN BOARD, COMPLETE (TH)
*********************
CN121 1-784-774-11 CONNECTOR, FFC 13P (TH)
CN121 1-784-776-11 CONNECTOR, FFC 15P (MY, SP, HK, CH)
IC501 8-759-656-80 IC M30622MA-A29FP
R582 1-249-415-11 CARBON 680 5% 1/4W
R583 1-249-425-11 CARBON 4.7K 5% 1/4W
(TH, CH)
R584 1-249-411-11 CARBON 330 5% 1/4W
(TH)
R584 1-249-415-11 CARBON 680 5% 1/4W
(CH)
R584 1-249-417-11 CARBON 1K 5% 1/4W
(MY, SP, HK)
A-4428-730-A PA BOARD, COMPLETE
*******************
C883 1-127-812-11 ELECT 3300uF 20% 63V
C884 1-127-812-11 ELECT 3300uF 20% 63V

13
A-4426-275-A PANEL BOARD, COMPLETE (NX3: E, AUS)
**********************
C714 1-162-282-31 CERAMIC 100PF 10% 50V
R707 1-249-433-11 CARBON 22K 5% 1/4W
Page STR-NX1/NX3 STR-NX300
Ref. No. Part No. Description Remark
Ref. No. Part No. Description Remark
A-4426-655-A PANEL BOARD, COMPLETE
**********************
C704 1-162-306-11 CERAMIC 0.01uF 30% 16V
C705 1-126-961-11 ELECT 2.2uF 20% 50V
C714 1-162-284-31 CERAMIC 150PF 10% 50V
C721 1-162-294-31 CERAMIC 0.001uF 10% 50V
C722 1-162-305-11 CERAMIC 0.0068uF 30% 16V
C723 1-126-960-11 ELECT 1uF 20% 50V
C724 1-136-495-11 MYLAR 0.068uF 5% 50V
C725 1-126-959-11 ELECT 0.47uF 20% 50V
C726 1-126-959-11 ELECT 0.47uF 20% 50V
C727 1-136-167-00 MYLAR 0.15uF 5% 50V
C728 1-162-294-31 CERAMIC 0.001uF 10% 50V
C729 1-126-960-11 ELECT 1uF 20% 50V
C730 1-161-494-00 CERAMIC 0.022uF 25V
C731 1-162-305-11 CERAMIC 0.0068uF 30% 16V
C732 1-136-495-11 MYLAR 0.068uF 5% 50V
C733 1-104-664-11 ELECT 47uF 20% 16V
C734 1-164-159-11 CERAMIC 0.1uF 50V
C735 1-104-664-11 ELECT 47uF 20% 16V
C736 1-126-961-11 ELECT 2.2uF 20% 50V
D701 8-719-109-85 DIODE MTZJ-T-72-5.1B
J703 1-785-569-11 JACK (SMALL TYPE) (MIC 2)
IC702 8-759-496-40 IC M65850FP
R701 1-249-429-11 CARBON 10K 5% 1/4W
R702 1-249-417-11 CARBON 1K 5% 1/4W
R707 1-249-437-11 CARBON 47K 5% 1/4W
R711 1-249-433-11 CARBON 22K 5% 1/4W
R712 1-249-401-11 CARBON 47 5% 1/4W
R713 1-249-433-11 CARBON 22K 5% 1/4W
R714 1-249-433-11 CARBON 22K 5% 1/4W
R715 1-249-437-11 CARBON 47K 5% 1/4W
R716 1-249-433-11 CARBON 22K 5% 1/4W
R717 1-249-433-11 CARBON 22K 5% 1/4W
R718 1-247-881-00 CARBON 120K 5% 1/4W
R719 1-249-431-11 CARBON 15K 5% 1/4W
R720 1-249-431-11 CARBON 15K 5% 1/4W
R721 1-249-433-11 CARBON 22K 5% 1/4W
S618 1-762-875-21 SWITCH, KEYBOARD (KARAOKE PON)
RV702 1-225-739-11 RES, VAR CARBON 50K (ECHO LEVEL)
0F951 1-532-505-31 FUSE T5AL/250V (MY, SP, HK)
0S951 1-771-291-11 SWITCH, POWER (VOLTAGE SELECTOR)
(MY, SP, HK)
0T951 1-435-279-11 TRANSSFORMER, POWER
0F951 1-533-949-31 FUSE T8AL/250V (NX3: MY, SP)
0S951 1-771-291-11 SWITCH, POWER (VOLTAGE SELECTOR)
(MY, SP, JE)
0T951 1-433-996-11 TRANSSFORMER, POWER (NX3: E AUS)
The components identified by
mark 0or dotted line with
mark 0are critical for safety.
Replace only with part num-
ber specified.
40
41
39

14
Page STR-NX1/NX3 STR-NX300
Ref. No. Part No. Description RemarkRef. No. Part No. Description Remark
41
MISCELLANEOUS
**************
4 1-751-688-11 WIRE (FLAT TYPE) (13CORE) (TH)
4 1-733-011-11 WIRE (FLAT TYPE) (15CORE)
(MY, SP, HK)
6 1-233-545-11 TUNER PACK (FM/MW/SW) (TH)
6 1-233-546-11 TUNER PACK (FM/MW/SW) (MY, SP, HK)
6 1-693-381-11 TUNER PACK (FM/MW/SW) (CH)
67 1-769-885-11 WIRE (FLAT TYPE) (7CORE)
0104 1-777-071-51 CORD, POWER (HK, MY, SP)
0104 1-783-205-11 CORD, POWER (CH)
0104 1-791-901-11 CORD, POWER (TH)
0107 1-770-019-11 ADAPTOR, CONVERSION 2P (HK)
0T951 1-435-279-11 TRANSFORMER, POWER
STR-NX300
Sony Corporation
Home Audio Division Company
9-929-045-11 2000A0570082-1
Printed in Singapore C2000. 1
Published by Quality Assurance Dept.
MISCELLANEOUS
**************
4 1-733-011-11 WIRE (FLAT TYPE) (15CORE)
(AEP, UK, MY, SP, JE)
6 1-233-546-11 TUNER PACK (FM/MW/SW) (MY, SP)
67 1-769-886-11 WIRE (FLAT TYPE) (7CORE)
0104 1-575-651-11 CORD, POWER (NX3: MY, SP)
0T951 1-433-996-11 TRANSFORMER, POWER (NX3: E, AUS)
The components identified by
mark 0or dotted line with
mark 0are critical for safety.
Replace only with part num-
ber specified.