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TX-NR901
SERVICE MANUAL
SERVICE MANUAL
AV RECEIVER
Black and Golden models
MODEL
TX-NR901
Ref. No. 3786
112003
BMDD,BMDC
120V, AC 60Hz
GMWT,GMWR
120/220~230V, AC 50/60Hz
BMPA,GMPA
230~240V, AC 50Hz
GMGK
220V, AC 50Hz
--/---
@. - ' /
ABC
DEF
PQRS
TUV
WXYZ
DIRECT TUNING
GHI
JKL
MNO
CAPS
DELETE
LANGUAGE LOCATION
ALBUM
ARTIST
GENRE
PLAYLIST
CUSTOM
DISPLAY
DIMMER
TV
INPUT
SLEEP
RANDOM
REC
STEP/SLOW
MUTING
ENTER
LAST M
ANGLE
SUBTITLE
AUDIO
MEMORY
SEARCH
A-B
REPEAT
ON
STANDBY
TV
TV CH
TV VOL
AUDIO
AD
J
EX
IT
GU
ID
E
+10
0
CLEAR
12
3
45
6
78
9
INPUT
TO
P M
ENU
MEN
U
SET
UP
RE
TURN
ZONE
2
INPUT
MODE
MACRO
VOL
CH
DISC
TEST TONE
CH SEL
PURE A
SURR
DIRECT
STEREO
Re-EQ
THX
All ST
LEVEL+
LEVEL-
L NIGHT
AUDIO SEL
DSP
DSP
+
-
+
-
STANDBY/ON
STANDBY
MASTER VOLUME
TUNER
PHONO
NET AUDIO
C D
TAPE
DVD
VIDEO
3
VIDEO
5
VIDEO
4
VIDEO
2
VIDEO
1
VCR
2
VCR
1
ZONE
2 ()
GRN
REC ()
RED
AUDIO
SELECTOR
DISPLAY
PURE AUDIO
UPSAMPLING
PUSH TO OPEN
SAFETY-RELATED COMPONENT
WARNING!!
COMPONENTS IDENTIFIED BY MARK
ON THE
SCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCK.
REPLACE THESE COMPONENTS WITH ONKYO
PARTS WHOSE PART NUMBERS APPEAR AS SHOWN
IN THIS MANUAL.
MAKE LEAKAGE-CURRENT OR RESISTANCE
MEASUREMENTS TO DETERMINE THAT EXPOSED
PARTS ARE ACCEPTABLY INSULATED FROM THE
SUPPLY CIRCUIT BEFORE RETURNING THE
APPLIANCE TO THE CUSTOMER.

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TX-NR901/E
SPECIFICATIONS
Amplifier Section
Video Section
Tuner Section
FM
AM
General
Video Inputs
Video Outputs
Audio Inputs
Audio Outputs
Other Sockets
Specifications and features are subject to change without
notice.
Power output:
All channels:
110 W (8
, 20 Hz­20 kHz, FTC)
(American Model)
180 W(6
, 1 kHz, EIAJ) (Asian Model)
150 W(6
, 1 kHz, DIN)
(Australian model)
Dynamic power:
2 x 280W (3
, front)
2 x 220W (4
, front)
2 x 140W (8
, front)
THD (total harmonic
distortion):
0.08% (rated power)
Damping factor:
60
Input sensitivity and
impedance:
200 mV/50k
(LINE)
2.5 mV/50k
(PHONO MM)
Output level and
impedance:
200 mV/470
(REC OUT)
Phono overload:
120 mV (MM, 1 kHz, 0.5%)
Frequency response: 10 Hz­100 kHz/+1 dB, ­3 dB (CD,
Direct)
Tone control:
±10 dB, 50 Hz (BASS)
±10 dB, 20,000 Hz (TREBLE)
S/N ratio (Direct mode):110 dB (LINE, IHF-A, 0.5 V input)
80 dB (PHONO, IHF-A, 5 mV input)
Speaker impedance:
4­16
Input sensitivity, output
level and impedance: 1.0Vp-p/75
(component and S-V ideo
Y)
0.7 Vp-p/75
(component PB/CB, PR/CR)
0.286 Vp-p/75
(S-Video C)
1.0 Vp-p/75
(composite)
Component video
frequenc y response:
5 Hz­50 MHz
Tuning frequency range:87.5­108.0 MHz
Usable sensitivity:
FM STEREO 17.2 dBf, 2.0 µV (75
IHF)
FM MONO 11.2 dBf, 1.0 µV (75
IHF)
S/N ratio:
FM STEREO 70 dB (IHF-A)
FM MONO 76 dB (IHF-A)
THD:
FM STEREO 0.3%
FM MONO 0.2%
FM stereo separation: 45 dB at 1 kHz, 30 dB at 100 Hz­10 kHz
Tuning frequency range:530­1710 kHz (American model)
522­1611 kHz (Other models)
Usable sensitivity:
30 µV
S/N ratio:
40 dB
THD:
0.7%
Power supply:
American model: AC120 V, 60 Hz
Australian model:AC 230­240 V, 50 Hz
Others models: AC 220­230V and 120V
switchable 50/60 Hz
Power consumption:
American model: 9.0 A
Australian and Worldwide models: 670 W
Standby power
consumption:
2.5 W
Dimensions
(W x H x D):
17-1/8" x 6-7/8" x 18-1/16"
(435 x 175 x 459 mm)
Weight:
American and Australian models:
42.5 Ibs. (19.3 kg)
Worldwide models: 42.3 lbs. (19.2 kg)
Component video inputs: 2 (Input 1, Input 2)
S-Video inputs:
6 (DVD, Video 1­5)
V ideo inputs:
6 (DVD, Video 1­5)
Component video
outputs:
1 (Component Monitor Out)
S-Video outputs:
3 (Video 1 Out,V ideo 2 Out,Video
Monitor Out)
Video outputs:
4 (Video 1 Out,V ideo 2 Out,Video
Monitor Out, Zone 2 Video Out)
Digital inputs:
8 (Optical 1­4, Optical Video 5 (fix ed, on
front panel), Coaxial 1­3)
Analog inputs:
8 (CD, Phono, Tape, DVD, Video 1­4,
Video 5)
Multichannel analog
inputs:
7.1 ch (Front L/R, Center, Surround L/R,
Surround Back L/R, Subw oofer)
Digital outputs:
2 optical
Analog outputs:
4 (Tape Out,Video 1 Out,Video 2 Out,
Zone 2 Out)
Pre outs:
8 (Front L/R, Center , Surround L/R,
Surround Back L/R or Zone 2 L/R,
Subwoofer)
Subw oofer pre out:
1
Speak er outputs:
7
Phones:
1
RS-232:
1 (not American and Australian models)
IR in/out:
1
12V trigger out:
1
Ethernet (Net-T une)
1 (10Base-T, RJ45)

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TX-NR901
SERVICE PROCEDURES 1
1. Replacing the fuses
This symbol located near the fuses indicates
that the fuse used is fast operating type. For continued
protection against fire hazard, replace with same type fuse.
For fuse rating refer to the marking adjacent to the symbol.
Ce symbole indique que le fusible utlise est a
rapide. Pour une protection permanente, n'untiliser que
fusibles de meme type. Ce darnier est la qu le present
symbol est appse.
2. To initialize the unit
This device employs a microprocessor to perform various
functions and operations. If interference generated by an
external power supply, radio wave, or other electrical source
results in accident which causes the specified operations
and functions to operate abnormally.
To perform a result, please follow the procedure below.
1.Press the STANDBY ON button to turn on the unit.
2.Press and hold down the VIDEO 1 button, then press the
STANDBY/ON button.
3.After "CLEAR" is displayed, the preset memory and each
mode stored in the memory, such as surround, are
initialized and will return to the factory setting.
4.Unplug the power supply cord.
3. Safety-check out
(Only U.S.A. model)
After correcting the original service problem, perform the
following safety check before releasing the set to the
customer. Connect the insulating-resistance tester between
the plug of power supply cord and screw on the back panel.
Specifications: 3.3Mohm+/-10% at 500V.
4. Memory Preservation
This unit does not require memory preservation batteries. A
built-in memory power back-up system preserves the contents
of the memory during power failures and even when the unit is
unplugged.The unit must be plugged in order to charge the
back-up system.
The memory preserv ation period after the unit has been
unplugged varies depending on climate and placement of the
unit. On the average, memory contents are protected over a
period of a fe w weeks after the last time the unit has been
unplugged.This period is shorter when the unit is exposed to a
highly humid climate.
5.Setting the voltage selector
(Worldwide models only)
Worldwide models are equipped with a voltage selector so
that you
supplies. Be
can set your TX-NR901 to conform with local power
sure to set this switch to match the voltage of
your area before plugging in the unit.
Determine the proper voltage for your area: 220-230 V or
the preset voltage is not correct for your area,
into the groove in the switch and slide
(220-230 V), whichever is appropriate.
Note: <D>: 120V model only
<A>: Australian model only
<T>: Worldwide model only
<R>: Chinese model only
the power supply in
120 V. If
insert a screwdriver
the switch all the way to the top (120 V) or bottom
REF. NO.
PART NO.
DESCRIPTION
F901
252196
12A-UL/T-314,Fuse <D/T/R>
F902
252078
5A-SE-EAK,
252244 or
5A-SE-TL250V or
252278
5A-SE-TL250V, Fuse <T/A/R/K>
F903
252164 or
5A-UL/T-237 or
252258
5A-T/UL-ST2,Fuse <D>
252075,
2.5A-SE-EAK,
252241 or
2.5A-SE-TL250V or
252275
2.5A-SE-TL250V,Fuse <T/A/R/K>
F9501,F9502
252160 or
2.5A-UL/T-237 or
252254
2.5A-T/UL-ST2,Fuse <D>
252075,
2.5A-SE-EAK,
252241 or
2.5A-SE-TL250V or
252275
2.5A-SE-TL250V,Fuse <T/A/R/K>
F9503,F9504
252158 or
1.6A-UL/T-237 or
252252
1.6A-T/UL-ST2,Fuse <D>
252073,
1.6A-SE-EAK,
252239 or
1.6A-SE-TL250V or
252273
1.6A-SE-TL250V,Fuse <T/A/R/K>
<K>: Korean model only
FM
75
OUT
OUT
OUT
OUT
L
OUT
PHONO
DIGITAL
IN
PRE OUT
DIGITAL
OUT
OPT
OPT
2
1
2
3
4
1
2
FRONT
SUB
SURR
R
L
AUDIO
R
L
CD
TAPE
R
L
AUDIO
VIDEO
S VIDEO
MONITOR
OUT
R
L
IN
IN
IN
IN
IN
IN
IN
ZONE 2
DVD
VIDEO 1
VIDEO 2
VIDEO 3
VIDEO 4
AUDIO
AUDIO
VIDEO
S VIDEO
1
3
GND
SURR
BACK/
ZONE 2
R
L
IN
AC INLET
COAX
R
ZONE 2
REMOTE
CONTROL
RS232
I R
12V TRIGGER OUT
IN
CENTER
ETHERNET
(Net -Tune)
R
L
MULTI CH
INPUT
FRONT
SUB
SURR
SURR
BACK
CENTER
R
L
AM
ANTENNA
COMPONENT
VIDEO
Y
PB
PR
OUTPUT
INPUT 1
Y
PB
PR
INPUT 2
Y
PB
PR
VOLTAGE
SELECTOR
220-230V
120V
TX-NR
901
MODEL NO. /
SURR
BACK/
ZONE 2
SPEAKERS
FRONT SPEAKERS
L
RL
R
SURR SPEAKERS
CENTER
SPEAKER
R
L
VOLTAGE
SELECTOR
220-230V
120V

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TX-NR901
SERVICE PROCEDURES 2
This section explains ho w to specify the AM frequenc y
step. (This setting is not available on American and Aus-
tralian models.)
Note:
* This procedure can also be performed by using the
TX-NR901's [SETUP] button, [
]/[
]/[
]/[
]
buttons, and [ENTER] button.
Specifying the AM Frequency Step
(Worldwide model only)
1
Press the scroll wheel, and then
press the [SETUP] button.
The main menu appears onscreen.
2
Use the Up/Down [
]/[
] but-
tons to select "0. Hardware
Setup," and then press the
[ENTER] button.
The Hardware Setup menu appears.
3
Use the Up/Down [
]/[
] but-
tons to select "5. AM Frequency
Step," and then press the
[ENTER] button.
The AM Frequenc y Step menu appears.
4
Use the Up/Down [
]/[
] but-
tons to select "a. Frequency
Step," and then use the Left/Right
[
]/[
] buttons to select:
10 kHz: Select if 10 kHz steps are
used in your area.
9 kHz: Select if 9 kHz steps are used
in your area.
5
Press the [SETUP] button.
The setup menu closes.
ENTER
ENTER
ENTER
ENTER
0-5.AM Frequency Step
a.Frequency Step
:9 kHz
Quit:[SETUP]
ENTER

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TX-NR901
FRONT PANEL
4
6
7
12
11
13
16
19
21
5
8
9
10
15
14
17
18
20
3
26
23
22
25
24
2
27
29
28
30
STANDBY/ON
STANDBY
MASTER VOLUME
TUNER
PHONO
NET AUDIO
C D
TAPE
DVD
VIDEO
3
VIDEO
5
VIDEO
4
VIDEO
2
VIDEO
1
VCR
2
VCR
1
ZONE
2 ()
GRN
REC ()
RED
AUDIO
SELECTOR
DISPLAY
PURE AUDIO
UPSAMPLING
OFF
ON
POWER
PUSH TO OPEN
PHONES
ZONE
2 LEVEL
STEREO SURROUND
THX
DSP
REC OUT
ZONE
2
OFF
DIMMER
MEMORY
FM MODE
SETUP
ENTER
RETURN
S VIDEO
VIDEO
DIGITAL
VIDEO
5 INPUT
STANDBY/ON
STANDBY
MASTER VOLUME
TUNER
PHONO
NET AUDIO
C D
TAPE
DVD
VIDEO
3
VIDEO
5
VIDEO
4
VIDEO
2
VIDEO
1
VCR
2
VCR
1
ZONE
2 ()
GRN
REC ()
RED
AUDIO
SELECTOR
DISPLAY
PURE AUDIO
UPSAMPLING
PUSH TO OPEN
PRESET
TUNING
CLEAR
AUDIO
LR
American and Australian Models
Other Models
Front door
Push here to open the flap
4
6
7
12
11
5
8
9
10
3
1
2