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SERVICE MANUAL
FM STEREO/FM-AM RECEIVER
US Model
Canadian Model
STR-DE845/DE945
E Model
Australian Model
Chinese Model
PX Model
STR-DE845
SPECIFICATIONS
STR-DE845/DE945
Photo: STR-DE945
Manufactured under license from Dolby labora-
tories. "Dolby", "AC-3", "Pro Logic" and the double-
D symbol ; are trademarks of Dolby Laborato-
ries.
Manufactured under license from Digital Theater
Systems, Inc. US Pat. No. 5,451,942 and other
worldwide patents issued and pending. "DTS" an
d "DTS Digital Surround" are trademarks of Digi-
tal Theater Systems, Inc.
­ Continued on next page ­
AUDIO POWER
SPECIFICATIONS
POWER OUTPUT AND
TOTAL HARMONIC
DISTORTION:
With 8 ohm loads, both
channels driven, from 20 -
20,000 Hz; rated 110 watts
(STR-DE945) and 100 watts
(STR-DE845) per channel
minimum RMS power,
with no more than 0.09 %
total harmonic distortion
from 250 milliwatts to
rated output (USA model
only).
Amplifier section
POWER OUTPUT
Models of area code U, CA
Rated Power Output at Stereo Mode
(8 ohms 20 Hz ­ 20 kHz, THD 0.09 %)
STR-DE945:
110 W + 110 W
STR-DE845:
100 W + 100 W
Reference Power Output
(8 ohms 1 kHz, THD 0.7 %)
STR-DE945:
FRONT:1)
110 W + 110 W
CENTER1): 110 W
REAR1):
110 W + 110 W
STR-DE845:
FRONT1):
100 W + 100 W
CENTER1): 100 W
REAR1):
100 W + 100 W
Models of other area code
STR-DE845:
Rated Power Output at Stereo Mode
(8 ohms 1 kHz, THD 0.7 %)
100 W + 100 W2)
90 W + 90 W3)
Reference Power Output
(8 ohms 1 kHz, THD 0.7 %)
FRONT1):
100 W + 100 W
CENTER1): 100 W
REAR1):
100 W + 100 W
(8 ohms 20 Hz ­ 20 kHz, THD 0.09 %)
FRONT1):
95 W + 95 W
CENTER1): 95 W
REAR1):
95 W + 95 W
(8 ohms 1 kHz, THD 10 %)
FRONT1):
135 W + 135 W
CENTER1): 135 W
REAR1):
135 W + 135 W
1) Depending on the sound field settings and
the source, there may be no sound output.
2) Measured under the following conditions:
Area code
Power requirements
AU, E
240 V AC, 50 Hz
CN, SP
230 V AC, 50 Hz
3) Measured under the following conditions:
Area code
Power requirements
CN
220 V AC, 50 Hz
Frequency response
PHONO: RIAA
equalization curve
±0.5 dB
CD, TAPE, MD/DAT,
MD/TAPE, DVD/
LD, TV/SAT,
VIDEO 1, 2, and
VIDEO 3:
10 Hz ­ 50 kHz
+0.5/­2 dB (with
sound field,
equalizer, and bass
boost bypassed)
Inputs (Analog)
PHONO:
Sensitivity: 2.5 mV
Impedance: 50
kilohms
S/N4): 86 dB
(A, 2.5 mV5))
5.1CH INPUT, CD,
TAPE, MD/DAT,
MD/TAPE, DVD/
LD, TV/SAT, VIDEO
1, 2, and VIDEO 3:
Sensitivity: 150 mV
Impedance:
50 kilohms
S/N4): 96 dB
(A, 150 mV5))
4) INPUT SHORT
5) Weighted network, input level
Inputs (Digital)
DVD/LD IN(Coaxial):
Sensitivity: ­
Impedance: 75 ohms
S/N: 100 dB
(A, 20 kHz LPF)
DVD/LD IN, TV/SAT
IN, MD/DAT IN
(Optical):
Sensitivity: ­
Impedance: ­
S/N: 100 dB
(A, 20 kHz LPF)
Outputs
TAPE, MD/DAT, MD/
TAPE; VIDEO 1, 2
(AUDIO OUT):
Voltage: 150 mV,
Impedance:
1 kilohms
SUB WOOFER:
Voltage: 2 V
Impedance:
1 kilohms
PHONES:
Accepts low- and
high-impedance
headphones
BASS BOOST
+6 dB at 70 Hz
Sampling Frequency
48 kHz
EQ
BASS:
100 Hz~1.0 kHz
(21 steps)
MID:
500 Hz~5.0 kHz
(21 steps)
TREBLE:
1.0 kHz~10 kHz
(21 steps)
Gain levels:
±10 dB, 1 dB step


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2
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH
MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS AP-
PEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0 SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.
Notes on chip component replacement
· Never reuse a disconnected chip component.
· Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
Flexible Circuit Board Repairing
· Keep the temperature of the soldering iron around 270 °C during
repairing.
· Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
· Be careful not to apply force on the conductor when soldering or
unsoldering.
FM tuner section
Tuning range
87.5 - 108.0 MHz
Antenna terminals
75 ohms, unbalanced
Sensitivity
Mono: 18.3 dBf,
2.2
µV/75 ohms
Stereo: 38.3 dBf,
22.5
µV/75 ohms
Usable sensitivity
11.2 dBf, 1
µV/75 ohms
S/N
Mono: 76 dB
Stereo: 70 dB
Harmonic distortion at 1 kHz
Mono: 0.3%
Stereo: 0.5%
Separation
45 dB at 1 kHz
Frequency response
30 Hz ­ 15 kHz
+0.5/­2 dB
Selectivity
60 dB at 400 kHz
AM tuner section
Tuning range
Models of area code U, CA
With 10-kHz tuning
scale:
530 ­ 1710 kHz6)
With 9-kHz tuning
scale:
531 ­ 1710 kHz6)
Models of area code AU, CN, SP
With 9-kHz tuning
scale:
531 ­ 1602 kHz
Models of area code E
With 10-kHz tuning
scale:
530 ­ 1610 kHz6)
With 9-kHz tuning
scale:
531 ­ 1602 kHz6)
Antenna
Loop antenna
Usable sensitivity
50 dB/m (at 1,000 kHz
or 999 kHz)
S/N
54 dB (at 50 mV/m)
Harmonic distortion
0.5 % (50 mV/m,
400 kHz)
Selectivity
At 9 kHz: 35 dB
At 10 kHz: 40 dB
6) You can change the AM tuning scale to
9 kHz y 10 kHz. After tuning in any AM
station, turn off the receiver. Hold down the
TUNING + button and press the ?/1 button.
All preset stations will be erased when you
change the tuning scale. To reset the scale
to 10 kHz (or 9 kHz), repeat the procedure.
Video section
Inputs
Video: 1 Vp-p 75 ohms
S-video:
Y: 1 Vp-p 75 ohms
C: 0.286 Vp-p
75 ohms
Outputs
Video: 1 Vp-p 75 ohms
S-video:
Y: 1 Vp-p 75 ohms
C: 0.286 Vp-p
75 ohms
AC outlets
Models of area code U,
CA
2 switched,
total 120 W/1A
Models of area code
AU, SP
1 switched,
total 100 W
Models of area code E,
CN
2 switched,
total 100 W
Dimensions
430
× 158 × 378 mm
(17
× 61/4 × 15 in.)
including projecting
parts and controls
Mass (Approx.)
10.3 kg (22 lb 12 oz)
Supplied accessories
· FM wire antenna (1)
· AM loop antenna (1)
· LR6 (size-AA) alkaline batteries (3)
Models of area code U, CA only
· Audio/video/control S
connecting cord (1)
· Control S connecting cord (1)
STR-DE945 only
· Remote commander RM-LJ304
(remote) (1)
STR-DE845 only
· Remote commander RM-LP204
(remote) (1)
Design and specifications are subject
to change without notice.
General
System
Tuner section:
PLL quartz-locked
digital synthesizer
system
Preamplifier section:
Low-noise NF type
equalizer
Power amplifier
section:
Pure-complementary
SEPP
Power requirements
Models of area code U,
CA
120 V AC, 60 Hz
Models of area code
CN, SP
220 ­ 230 V AC,
50/60 Hz
Models of area code AU
240 V AC, 50 Hz
Models of area code E
120/220/240 V AC,
50/60 Hz
Power consumption
Models of area code U
STR-DE945: 290 W
STR-DE845: 280 W
Models of area code CA
STR-DE945: 345 VA
STR-DE845: 335 VA
Models of area code
CN, SP
STR-DE845: 220 W
Models of area code AU
STR-DE845: 230 W
Models of area code E
STR-DE845: 320 W
· Abbreviation
AU : Australian model
CA : Canadian model
CN : Chinese model
MY : Malaysia model
SP : Singapore model
U
: US model


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3
MODEL IDENTIFICATION
­ Rear View ­
Part No.
Fig. A.
Using an AC voltmeter to check AC leakage.
1.5 k
0.15
µF
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, "metallized" knobs,
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes.).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers' instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The "limit" indication is 0.75
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2 V AC range are suitable. (See Fig. A)
TABLE OF CONTENTS
1.
GENERAL ................................................................... 4
2.
DISASSEMBLY ......................................................... 6
3.
TEST MODE .............................................................. 9
4.
DIAGRAMS
4-1. Block Diagram ­ MAIN Section (1/2) ­ ........................ 11
4-2. Block Diagram ­ MAIN Section (2/2) ­ ........................ 12
4-3. Block Diagram
­ DISPLAY/POWER SUPPLY Section ­ ...................... 13
4-4. Note for Printed Wiring Boards and
Schematic Diagrams ...................................................... 14
4-5. Schematic Diagram ­ DIGITAL Board (1/3) ­ .............. 15
4-6. Schematic Diagram ­ DIGITAL Board (2/3) ­ .............. 16
4-7. Schematic Diagram ­ DIGITAL Board (3/3) ­ .............. 17
4-8. Printed Wiring Board
­DIGITAL Board (Component Side) ............................. 18
4-9. Printed Wiring Board
­DIGITAL Board (Conductor Side) ............................... 19
4-10. Printed Wiring Boards
­VIDEO/JOINT (1) (H) Boards (DE845) ­ ................... 20
4-11. Schematic Diagram
­VIDEO/JOINT (1) (H) Boards (DE845) ­ ................... 21
4-12. Printed Wiring Boards
­ OSD/OSD JOINT (H) Boards (DE945) ­ ................... 22
4-13. Schematic Diagram
­ OSD/OSD JOINT (H) Boards (DE945) ­ ................... 23
4-14. Printed Wiring Board ­ AU SW Board ­ ....................... 24
4-15. Schematic Diagram ­ AU SW Board ­ .......................... 25
4-16. Printed Wiring Board ­ S-VIDEO Board ­ .................... 26
4-17. Schematic Diagram ­ S-VIDEO Board ­ ....................... 27
4-18. Printed Wiring Board ­DISPLAY Board ­ .................... 28
4-19. Schematic Diagram ­ DISPLAY Board ­ ...................... 29
4-20. Printed Wiring Board ­ MAIN Board ­ ......................... 30
4-21. Schematic Diagram ­ MAIN Board (1/3) ­ ................... 31
4-22. Schematic Diagram ­ MAIN Board (2/3) ­ ................... 32
4-23. Schematic Diagram ­ MAIN Board (3/3) ­ ................... 33
4-24. Printed Wiring Boards ­ H.P/MUTING/POWER/
ROTARY/VIDEO 3(DE945)/VOL/
V. SWITCH (E) Boards ­ ............................................... 34
4-25. Schematic Diagram ­ H.P/MUTING/POWER/
ROTARY/VIDEO 3(DE945)/VOL/
V. SWITCH (E) Boards ­ ............................................... 35
4-26. Printed Wiring Boards ­ BIAS (C)/BIAS (L)
/BIAS (R)/BIAS (LS)/BIAS (RS)/5.1 IN Boards ­ ....... 36
4-27. Schematic Diagram ­ BIAS (C)/BIAS (L)
/BIAS (R)/BIAS (LS)/BIAS (RS)/5.1 IN Boards ­ ....... 37
4-28. Printed Wiring Boards ­DC (1)/DC (2) Boards ­ .......... 38
4-29. Schematic Diagram ­DC (1)/DC (2) Boards ­ .............. 39
4-30. Printed Wiring Boards ­AC/SP Boards ­ ....................... 40
4-31. Schematic Diagram ­ AC/SP Boards ­ .......................... 41
4-32. IC Pin Function Description ........................................... 46
5.
EXPLODED VIEWS ................................................ 56
6.
ELECTRICAL PARTS LIST ............................... 59
Model
DE945:
US model
DE945:
Canadian model
DE845:
US model
DE845:
Canadian model
Malaysia and Singapore models
Chinese model
Australian model
E and PX models
Part No.
4-226-871-0s
4-226-871-1s
4-226-871-3s
4-226-871-4s
4-226-871-5s
4-226-871-6s
4-226-871-7s
4-226-871-8s


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4
SECTION 1
GENERAL
Location of controls
­ Front view ­
1 I/1 button
2 Function Buttons
3 INPUT MODE button
4 5.1CH INPUT button
8 DIMMER button
9 DISPLAY button
q; A. F. D button/indicator
2CH button/indicator
MODE button/indicator
qa CINEMA STUDIO EX. A ­ C buttons
qs MULTI CHANNEL DECORDING indicator
qd PRESET TUNING +/­ buttons
SHIFT button
TUNING +/­ buttons
FM/AM button
FM MODE button
qf 2ND AUDIO button (STR-DE945)
qg BASS BOOST button
qh EQUALIZER button
qj SET UP button
qk NAME button
ql ENTER button
w; cursor buttons (</>)
wa Jog dial
ws EQ button
wd SUR button
wf LEVEL button
5 MASTER VOLUME control
6 MUTING button
7 SPEAKERS button
PHONE jack
+
­
PHONES
SPEAKERS
DIMMER
DISPLAY
INPUT MODE
VIDEO 1 VIDEO 2 VIDEO 3 DVD/LD TV/SAT
CINEMA STUDIO EX.
MULTI CHANNEL DECODING
TAPE
MD/DAT
CD
TUNER PHONO
5.1CH INPUT
A
B
OFF
A+B
SOUND FIELD
A.F.D.
AB
C
2CH
MODE
LEVEL
SUR
EQ
SET UP
MASTER VOLUME
BASS BOOST
EQUALIZER
NAME
ENTER
010
VIDEO 3 INPUT
MUTING
BASS
BOOST
PRESET
TUNING
TUNING
­+
­+
MEMORY
FM/AM FM MODE 2ND AUDIO
SHIFT
EQUALIZER
VIDEO
L AUDIO R
5.1CH
INPUT
12
3 4
5
6
7
4
+
­
PHONES
SPEAKERS
DIMMER
DISPLAY
INPUT MODE
VIDEO 1 VIDEO 2 VIDEO 3 DVD/LD TV/SAT
CINEMA STUDIO EX.
MULTI CHANNEL DECODING
TAPE
MD/DAT
CD
TUNER PHONO
5.1CH INPUT
A
B
OFF
A+B
SOUND FIELD
A.F.D.
AB
C
2CH
MODE
LEVEL
SUR
EQ
SET UP
MASTER VOLUME
BASS BOOST
EQUALIZER
NAME
ENTER
010
VIDEO 3 INPUT
MUTING
BASS
BOOST
PRESET
TUNING
TUNING
­
+
­
+
MEMORY
FM/AM FM MODE 2ND AUDIO
SHIFT
EQUALIZER
VIDEO
L AUDIO R
89
0qa
qs
qd
qf
qg
qj
ql
qh
qk
w;
wa
wd
wf ws
(STR-DE945 only)
(STR-DE845 only)


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5
1 ANTENNA terminal
2 5.1CH INPUT jack
3 DIGITAL jack
OPTICAL jack
COAX jack
4 SPEAKERS terminal
FRONT (A/B) terminal
REAR terminal
CENTER terminal
5 SUB WOOFER jack
6 IMPEDANCE SELECTOR switch
7 AC POWER cord
8 AC OUTLET
9 CONTROL A1II jack
q; 2ND AUDIO OUT jack
­ Rear View ­
qa VIDEO 1 jack
qs VIDEO 2 jack
qd DVD/LD jack
qf TV/SAT jack
qg TAPE jack (STR-DE945)
qh MD/DAT jack (STR-DE945)
MD/TAPE jack (STR-DE845)
qj CD jack
qk PHONO jack
ql MONITOR jack
4
8
BA
RL
RL
+
­
+
­
IMPEDANCE USE 4 ­ 16
8 ­ 16
SPEAKERS
IN
L
R
OUT
SIGNAL
GND
COAXIAL
AM
U
U
ANTENNA
TAPE
IMPEDANCE SELECTOR
FRONT
IN
PHONO
IN
CD
2ND AUDIO
OUT
REAR
FRONT
CENTER
MONITOR
IN
OUT
MD/DAT
AUDIO IN
VIDEO IN
S-VIDEO
IN
VIDEO OUT
S-VIDEO
OUT
VIDEO IN
CTRL S
OUT
VIDEO OUT
VIDEO OUT
CTRL S
OUT
VIDEO IN
S-VIDEO
IN
S-VIDEO
IN
VIDEO IN
S-VIDEO
OUT
CTRL S
STATUS IN
CTRL S
IN
AUDIO OUT
VIDEO 1
AUDIO IN
TV/SAT
AUDIO IN
DVD/LD
AUDIO IN
AUDIO OUT
VIDEO 2
FM
75
+
­
+
­
RL
RL
AC OUTLET
SUB WOOFER
AUDIO
OUT
CONTROL A1
DVD/LD
IN
DVD/LD
IN
TV/SAT
IN
MD/DAT
IN
MD/DAT
OUT
DIGITAL
OPTICAL
COAX
L
R
REAR
FRONT
CENTER
SUB
WOOFER
5.1CH INPUT
4
8
5
6
23
1
qfqd
qs
qa
q;
9
qg
qh
qj
qk
ql
7
Setting
(E model)
a voltage selector
If your receiver has a voltage selector on the rear panel,
check that the voltage selector on the rear panel of the
receiver is set to the local power supply voltage. If not,
use a screwdriver to set the selector to the correct position
before connecting the AC power cord to a wall outlet.
220V
240V
120V
VOLTAGE SELECTOR