Pioneer VSX-523-K Service manual

2013

VSX-523-K

AV Receiver

VSX-523-K

THIS MANUAL IS APPLICABLE TO THE FOLLOWING MODEL(S) AND TYPE(S).

Model Type Power Requirement Remarks

VSX-523-K CUXESM AC 120 V

ORDER NO.

RRV4418

PIONEER CORPORATION 1-1, Shin-ogura, Saiwai-ku, Kawasaki-shi, Kanagawa 212-0031, Japan

PIONEER ELECTRONICS (USA) INC. P.O. Box 1760, Long Beach, CA 90801-1760, U.S.A.
PIONEER EUROPE NV Haven 1087, Keetberglaan 1, 9120 Melsele, Belgium
PIONEER ELECTRONICS ASIACENTRE PTE. LTD. 253 Alexandra Road, #04-01, Singapore 159936

PIONEER CORPORATION

K-MZV MAR.

2013 Printed in Japan

1

WARNING

This product may contain a chemical known to the State of California to cause cancer, or birth defects or other reproductive
harm.

Health & Safety Code Section 25249.6 - Proposition 65

This service manual is intended for qualified service technicians; it is not meant for the casual do-it­yourselfer. 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.

1. SAFETY PRECAUTIONS

The following check should be performed for the
continued protection of the customer and service
technician.

LEAKAGE CURRENT CHECK

Measure leakage current to a known earth ground
(water pipe, conduit, etc.) by connecting a leakage
current tester such as Simpson Model 229-2 or
equivalent between the earth ground and all exposed
metal parts of the appliance (input/output terminals,
screwheads, metal overlays, control shaft, etc.). Plug
the AC line cord of the appliance directly into a 120 V
AC 60 Hz outlet and turn the AC power switch on. Any
current measured must not exceed 0.5 mA.

ANY MEASUREMENTS NOT WITHIN THE LIMITS
OUTLINED ABOVE ARE INDICATIVE OF A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED BEFORE
RETURNING THE APPLIANCE TO THE CUSTOMER.

2. PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in the appliance

have special safety related characteristics. These are
often not evident from visual inspection nor the protection
afforded by them necessarily can be obtained by using
replacement components rated for voltage, wattage, etc.
Replacement parts which have these special safety
characteristics are identified in this Service Manual.
Electrical components having such features are
identified by marking with a > on the schematics and on
the parts list in this Service Manual.
The use of a substitute replacement component which
does not have the same safety characteristics as the
PIONEER recommended replacement one, shown in the
parts list in this Service Manual, may create shock, fire,
or other hazards.
Product Safety is continuously under review and new
instructions are issued from time to time. For the latest
information, always consult the current PIONEER Service
Manual. A subscription to, or additional copies of,
PIONEER Service Manual may be obtained at a nominal
charge from PIONEER.

Leakage
current
tester

Reading should
not be above

0.5 mA

Device
under
test

Test all
exposed metal
surfaces

Also test with
plug reversed
(Using AC adapter
plug as required)

Earth
ground

AC Leakage Test

(FOR USA MODEL ONLY)

2 3 4

SAFETY INFORMATION

A

B

C

D

E

F

2

1

2 3 4

VSX-523-K

5

6 7 8

CONTENTS

SAFETY INFORMATION.......................................................................................................................................................... 2

1. SERVICE PRECAUTIONS ....................................................................................................................................................4

1.1 NOTES ON SOLDERING...............................................................................................................................................4

1.2 NOTES ON REPLACING PARTS ................................................................................................................................... 4

1.3 SERVICE NOTICE.......................................................................................................................................................... 4

2. SPECIFICATIONS ................................................................................................................................................................. 5

3. BASIC ITEMS FOR SERVICE .............................................................................................................................................. 6

3.1 CHECK POINTS AFTER SERVICING ........................................................................................................................... 6

3.2 JIGS LIST ....................................................................................................................................................................... 6

3.3 PCB LOCATIONS ...........................................................................................................................................................7

4. BLOCK DIAGRAM ................................................................................................................................................................8

4.1 OVERALL WIRING DIAGRAM ....................................................................................................................................... 8

4.2 AUDIO BLOCK DIAGRAM............................................................................................................................................10

4.3 POWER SUPPLY BLOCK DIAGRAM........................................................................................................................... 12

4.4 GND BLOCK DIAGRAM............................................................................................................................................... 14

5. DIAGNOSIS ........................................................................................................................................................................ 16

5.1 TROUBLESHOOTING..................................................................................................................................................16

5.2 USB/iPod ERROR MESSAGE......................................................................................................................................21

5.3 PROTECTION CIRCUIT............................................................................................................................................... 22

5.4 IC INFORMATION ........................................................................................................................................................ 24

6. SERVICE MODE................................................................................................................................................................. 27

7. DISASSEMBLY ................................................................................................................................................................... 31

8. EACH SETTING AND ADJUSTMENT................................................................................................................................37

8.1 ADJUSTMENT REQUIRED WHEN THE UNIT IS REPAIRED OR REPLACED .......................................................... 37

8.2 UPDATING OF THE FIRMWARE .................................................................................................................................38

8.3 IDLE CURRENT ADJUSTMENT ..................................................................................................................................43

9. EXPLODED VIEWS AND PARTS LIST............................................................................................................................... 44

9.1 PACKING SECTION .....................................................................................................................................................44

2 EXTERIOR SECTION .................................................................................................................................................. 46

9.

10. SCHEMATIC DIAGRAM .................................................................................................................................................... 50

10.1 MAIN ASSY (1/2)........................................................................................................................................................50

10.2 MAIN ASSY (2/2)........................................................................................................................................................52

10.3 D-MAIN ASSY (1/3) .................................................................................................................................................... 54

10.4 D-MAIN ASSY (2/3) .................................................................................................................................................... 56

10.5 D-MAIN ASSY (3/3) .................................................................................................................................................... 58

10.6 OPTCO, FUSB and CONCT ASSYS..........................................................................................................................60

10.7 CPU ASSY.................................................................................................................................................................. 62

10.8 AMP5 ASSY (1/2) .......................................................................................................................................................64

10.9 AMP5 ASSY (2/2) .......................................................................................................................................................66

10.10 INSEL, FRONT and HPMIC ASSYS ........................................................................................................................68

10.11 SMPS ASSY .............................................................................................................................................................70

10.12 REG ASSY ............................................................................................................................................................... 72

11. PCB CONNECTION DIAGRAM........................................................................................................................................ 74

11.1 MAIN ASSY ................................................................................................................................................................74

11.2 D-MAIN, OPTCO and FUSB ASSYS.......................................................................................................................... 78

11.3 CONCT and CPU ASSYS .........................................................................................................

11.4 AMP5 ASSY ...............................................................................................................................................................86

11.5 INSEL, FRONT and HPMIC ASSYS ..........................................................................................................................88

11.6 SMPS and REG ASSYS............................................................................................................................................. 92

11.7 WG, G-L and G-R ASSYS .......................................................................................................................................... 96

12. PCB PARTS LIST .............................................................................................................................................................. 97

.................................82

A

B

C

D

E

F

VSX-523-K

5

6 7 8

3

1

• For environmental protection, lead-free solder is used on the printed circuit boards mounted in this unit.
Be sure to use lead-free solder and a soldering iron that can meet specifications for use with lead-free solders for repairs
accompanied by reworking of soldering.

• Compared with conventional eutectic solders, lead-free solders have higher melting points, by approximately 40 ºC.
Therefore, for lead-free soldering, the tip temperature of a soldering iron must be set to around 373 ºC in general, although
the temperature depends on the heat capacity of the PC board on which reworking is required and the weight of the tip of
the soldering iron.

Do NOT use a soldering iron whose tip temperature cannot be controlled.

Compared with eutectic solders, lead-free solders have higher bond strengths but slower wetting times and higher melting
temperatures (hard to melt/easy to harden).

The following lead-free solders are available as service parts:

• Parts numbers of lead-free solder:
GYP1006 1.0 in dia.
GYP1007 0.6 in dia.
GYP1008 0.3 in dia.

The part listed below is difficult to replace as a discrete component part.
When the part listed in the table is defective, replace whole Assy.

Assy Name

D-MAIN Assy

5V SW Power Supply IC

—————— IC with heat-padIC2007

INTERFACE IC —————— IC with heat-padIC2012

D-MAIN 1.2 V Power Supply IC —————— IC with heat-padIC2013

D-MAIN 1.8 V Power Supply IC —————— IC with heat-padIC2015

DSP IC —————— IC with heat-padIC2016

Low Dropout Power Supply IC —————— IC with heat-padIC2017

APPLE AUTHENTICATION IC —————— IC with heat-padIC2020

USB 5 V Power Supply IC —————— IC with heat-padIC2021

Parts that is Difficult to Replace

Ref No. Function Part No. Remarks

• Discharging

For more detail, please refer to "7. DISASSEMBLY - 1. Discharging".

2 3 4

1. SERVICE PRECAUTIONS

1.1 NOTES ON SOLDERING

A

B

C

1.2 NOTES ON REPLACING PARTS

D

E

1.3 SERVICE NOTICE

F

4

1

2 3 4

VSX-523-K

5

Amplifier section

Continuous average power output of 80 watts* per channel, min., at
8 ohms, from 20 Hz to 20 000 Hz with no more than 0.08 %** total

harmonic distortion.

Front (stereo)............................................................ 80 W + 80 W

Power output (1 kHz, 6 Ω, 1 %)........................... 140 W per channel

Guaranteed speaker impedance .....................................6 Ω to 16 Ω

* Measured pursuant to the Federal Trade Commission’s Trade
Regulation rule on Power Output Claims for Amplifiers
** Measured by Audio Spectrum Analyzer

Audio Section

Input (Sensitivity/Impedance)

LINE......................................................................... 200 mV/47 kΩ

Signal-to-Noise Ratio (IHF, short circuited, A network)

LINE.......................................................................................98 dB

Signal-to-Noise Ratio [EIA, at 1 W (1 kHz)]

LINE.......................................................................................79 dB

Video Section

Signal level

Composite .................................................................1 Vp-p (75 Ω)

Tuner Section

Frequency Range (FM) ................................. 87.5 MHz to 108 MHz

Antenna Input (FM)................................................75 Ω unbalanced

Frequency Range (AM) ...................................530 kHz to 1700 kHz

Antenna (AM) .............................................................Loop antenna

Digital In/Out Section

HDMI terminal ...........................................................Type A (19-pin)

HDMI output type............................................................5 V, 100 mA

USB (iPod) terminal................. USB2.0 Full Speed (Type A) 5 V, 1 A

Miscellaneous

Power Requirements............................................... AC 120 V, 60 Hz

Power Consumption ................................................................ 415 W

In standby.................................................................................0.1 W

Dimensions....................435 mm (W) x 168 mm (H) x 331.5 mm (D)

17

3/16

in. (W), 6

5/8

in. (H), 13

1/16

in. (D)

Weight (without package)..................................... 8.3 kg (18 lb 5 oz)

Note

• Specifications and the design are subject to possible
modifications without notice, due to improvements.

Accessories

Remote control (AXD7690)
(8300769000010-IL)

AM loop antenna
(E601019000010-IL)

Warranty card
Quick start guide (5707000007800-IL)
Safety Brochure
SPEAKER CAUTION Sheet (English only)
Operating instructions (CD-ROM)(6517000001280-IL)

FM wire antenna
(E605010140010-IL)

Dry cell batteries
(AAA size IEC R03) x2

Microphone (for Auto MCACC setup)
(APM7011)

2. SPECIFICATIONS

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

5

1

Items to be checked after servicing

To keep the product quality after servicing, confirm recommended check points shown below.

See the table below for the items to be checked regarding video and audio.

No.

Item to be checked regarding video Item to be checked regarding audio

Procedures Check points

1 Confirm whether the customer complain has been solved.

If the customer complain occurs with the particular source, such
as Dolby Digital, DTS, AAC, DVD-A and HDMI, input it for the
operation check.

The customer complain must not be reappeared.
Video, Audio and operations must be normal.

2 Check the analog audio playback.

(Make the analog connections with a DVD player.)

Each channel audio and operations must be normal.

3 Check the digital audio playback.

(Make the digital connections with a DVD player.)

Each channel audio and operations must be normal.

4 Check surround playback.

(Select Surround mode and check the multichannel operations
via the DSP circuit.)

Each channel audio and operations must be normal.

5 Check the video outputs.

(Connect with a DVD player.)

Video and operations must be normal.

6 Check the tuner (AM and FM) operations. Audio and operations must be normal.

7 Check the sound from headphone output. Sound must be normal, without noise.

8 Check the appearance of the product.

Block noise Distortion

Horizontal noise Noise

Flicker Volume too low

Disturbed image (video jumpiness) Volume too high

Too dark Volume fluctuating

Too bright Sound interrupted

Mottled color

No scratches or dirt on its appearance after receiving it for
service.

Jigs List

Jig Name Part No. Remarks

RS-232C update jig (Jig + 10P FFC) GGF1642

(Marketing product)

(Marketing product)

MAIN microcomputer firmware update
(RS-232C ↔ Rear panel)

RS-232C cable (9-pin to 9-pin, straight cable)

Diagnosis (D-MAIN Assy ↔ CPU Assy)Board to board extension jig cable GGD1847

Diagnosis (D-MAIN Assy ↔ CONCT Assy)Board to board extension jig cable GGD1848

Diagnosis (D-MAIN Assy ↔ CPU Assy)Board to board extension jig cable GGD1846

Lubricants and Glues List

Name Part No. Remarks

Silicon grease GEM1057 Refer to "9.2 EXTERIOR SECTION".

Silicon adhesive

GYA1011
(KE40RTV-W)

Refer to "9.2 EXTERIOR SECTION".

HDMI & CEC (SUB) microcomputer firmware update
(USB ↔ Rear panel)

RS-232C update jig GGF1646

USB cable (USB A-Type ↔ USB B-Type)

2 3 4

3. BASIC ITEMS FOR SERVICE

3.1 CHECK POINTS AFTER SERVICING

A

B

C

D

3.2 JIGS LIST

E

F

6

1

2 3 4

VSX-523-K

5

NSP 1..PCB TTL ASSY MAIN 7025HK1211010-IL

2..MAIN ASSY (PCB SUB ASSY MAIN) 7028073311010-IL

2..REG ASSY (PCB SUB ASSY REG) 7028073312010-IL

2..OPTCO ASSY (PCB SUB ASSY OPTCO)

7028073313010-IL

2..WG ASSY (PCB SUB ASSY WG) 7028073315010-IL

2..G-L ASSY (PCB SUB ASSY G-L) 7028073316010-IL

2..G-R ASSY (PCB SUB ASSY G-R) 7028073317010-IL

NSP 1..PCB TTL ASSY DMAIN 7025HK1211012-IL

2..D-MAIN ASSY (PCB SUB ASSY DMAIN)

7028073351010-IL

NSP 1..PCB TTL ASSY CPU 7025HK1211013-IL

2..CPU ASSY (PCB SUB ASSY CPU) 7028073331010-IL

NSP 1..PCB TTL ASSY AMP5 7025HK1211014-IL

2..AMP5 ASSY (PCB SUB ASSY AMP5) 7028073341010-IL

NSP 1..PCB TTL ASSY FRONT 7025HK1211011-IL

2..FRONT ASSY (PCB SUB ASSY FRONT)

7028073321010-IL

2..HPMIC ASSY (PCB SUB ASSY HPMIC)

7028073322010-IL

2..FUSB ASSY (PCB SUB ASSY FUSB) 7028073323010-IL

2..INSEL ASSY (PCB SUB ASSY INSEL) 7028073324010-IL

2..CONCT ASSY (PCB SUB ASSY CONCT)

7028073325010-IL

NSP 1..PCB TTL ASSY SMPS 7025HK1211015-IL
> 2..SMPS ASSY (PCB SUB ASSY SMPS) 7028073361010-IL

Mark No. Description Part No. Mark No. Description Part No.

LIST OF ASSEMBLIES

NOTES: - Parts marked by “NSP” are generally unavailable because they are not in our Master Spare Parts List.

-

The > mark found on some component parts indicates the importance of the safety factor of the part.

Therefore, when replacing, be sure to use parts of identical designation.

B

D-MAIN ASSY

F

CPU ASSY

E

CONCT ASSY

G

AMP5 ASSY

D

FUSB ASSY

I

FRONT ASSY

C

OPTCO ASSY

A

MAIN ASSY

J

HPMIC ASSY

H

INSEL ASSY

L

REG ASSY

WG ASSY

G-L ASSY

K

SMPS ASSY

G-R ASSY

3.3 PCB LOCATIONS

6 7 8

A

B

C

D

5

VSX-523-K

6 7 8

E

F

7

1

C

OPTCO ASSY
(7028073313010-IL)

J

HPMIC ASSY
(7028073322010-IL)

AMP5 ASSY
(70280733410

G

G G

1/2,

2/2

MAIN ASSY
(7028073311010-IL)

A

A A

1/2,

2/2

!

I

FRONT ASSY
(7028073321010-IL)

L

REG ASSY
(7028073312010-IL)

H

INSEL ASSY
(7028073324010-IL)

K

SMPS ASSY

(7028073361010-IL)

B E

E

C

B

B C E

EE

C

B

E

C

B

(S2)

AC-IN

(S4)

(S1)

Q102FR

Q103FR

C

Q102FR

Q103

C

MAIN TRANS

2SB1560

CP702A

KTC3964

Q101FR

2SB1560

KTC3964

Q101FR

AC CORD
or INLET

2SD2390

FR

2SD2

SR

CN1

CN3

CP2008

CN2010

CN101

4. BLOCK DIAGRAM

4.1 OVERALL WIRING DIAGRAM

A

2 3 4

B

C

D

E

F

8

1

2 3 4

VSX-523-K

5

D

FUSB ASSY

(7028073323010-IL)

D-MAIN ASSY (7028073351010-IL)

B

B B

1/3 - 3/3

F

CPU ASSY

(7028073331010-IL)

E

CONCT ASSY
(7028073325010-IL)

B C E

E B

ECB

E

B E

C

B

BCE

ECB

BC

A-12V

AGND1

AGND1

V+5V
AGND1

E

ECB

BC

E

E

C

B

A+12V

PDN

Q103FR

Q102FR

C

Q102FR

Q103FR

C

Q102FR

Q103FR

Q103FR

KTC3964

2SB1560

Q101FR

KTC3964

2SB1560

KTC3964

RF101QRF101Q

2SB1560

KTC3964

Q101FR

2SD2390

SR

2SD2390

SLC

0932DS20932DS2

FL

TUNER PACK

CN206 CN704B

CP2006

CN208CN209A

CN211

CP15CP16

CN204

CP13

CN203A

CN204

CP2008

CN2010

CN101

CN201

CN201

CP110

CN2006

CN110

CN109

CN2003

-

When ordering service parts, be sure to refer to "EXPLODED VIEWS and PARTS LIST" or "PCB PARTS LIST".

-

The > mark found on some component parts indicates the impor tance of the safety factor of the part.

Therefore, when replacing, be sure to use parts of identical designation.

-

: The power supply is shown with the marked box.

6 7 8

A

B

C

D

5

E

6 7 8

VSX-523-K

F

9

1

A

MAIN ASSY

• AUDIO PART

B

D-MAIN ASSY

Q426

IC2016

Q419

Q428

Q427

Q425

4.2 AUDIO BLOCK DIAGRAM

A

B

2 3 4

C

D

E

F

10

1

2 3 4

VSX-523-K

F

CPU ASSY

I FRONT ASSY

J

HPMIC ASSY

A

MAIN ASSY

G

AMP5 ASSY

C

OPTCO ASSY

D

FUSB ASSY

Q11

Q2Q3Q4

Q10

Q9

5

6 7 8

A

B

C

D

E

5

VSX-523-K

6 7 8

F

11

1

A

MAIN ASSY

F

C

L

REG ASSY

K

SMPS ASSY

10N

C118

IC100

NC

IC100

SMPS+5.6V

(0.1UF SIZE)

C141 5600/6.3(NXA)

PC123X2YFZ

SMPS+5.6V

F100

C109 NM

PC123X2YFZ

10

R128

R111

1K

R133

330

C134

1N-100V

6K8

R118

4K7

R112

12K-F

R109

L102
10UH

6.8V

ZD401

ZD102

LUDZS6.8B

CPU 3 3V

6M8(1/2W)

R100

0.1/275V

C101

1 2

4

3

LF4ZBE273H

L100

100/400(MHA)

C102

R106

120K(2W)

1000P/1KV

C103

KIA2431AP

IC116

R120

4.7(1W)

R108

12K-F

C129

220/10(AXA)

ST_H+5V

ZD101

LUDZS6.8B

CN901W

CN901B

RB160VA

A-6.8V

AC
CORD

R116

0.68(1W)

UF4007

D119

C148
33/63

SARS01

D108

S4(FLT)

S1(AMP B+/B-)

1500P/250V

C115

100N-K

C113

S30SC6MT

D103

KIA7912PI

KIA7812API

ZJ16B

ZJ16B

AP1117-3.3

KIA7805API

6.8V

ZD400

A-12V

A+6.8V

AUDIO PART

A+12V

S2(+12V,-12V)

MAIN
TRANS

5

4

8

9

6

3

1

2

7

10

11

12

EE2525V

T101

2 3 4

4.3 POWER SUPPLY BLOCK DIAGRAM

A

B

C

D

E

F

12

VSX-523-K

1

2 3 4

5

F

CPU ASSY

I

FRONT ASSY

G

AMP5 ASSY

C

OPTCO ASSY

D

FUSB ASSY

B

D-MAIN ASSY

SUB_ON

A-6.8V

A+12V

A+6.8V

TUNER+5V

V+5V

SMPS+5.6V

DMAIN+3.3V

USB+5V

H+5V

-

-

TX+5V

DSP+1.8V(USB)

H+1.8V

ZD102

LUDZS6.8B

CPU_3.3V

SMPS+5.6V

SMPS+5.6V

STBY_RLY

CPU_3.3V

H+5V_FETON

-

DSP+3.3V_FETON

-

RAQ045P01

Q2040

H+1.8V_ON

RAQ045P01

Q2036

0

IC2015

AP1117-1.8V

D+3.3V

DSP+1.2V

DSP+3.3V(USB)

H+3.3V

ST_H+5V

ZD101

LUDZS6.8B

Q2010

D+3.3V_ON

IC2017

AZ1068

CPU_3.3V

A-6.8V

USB+5V

USB5V_DET

D+5V_FETON

D+1.2V_ON

FL_AC2

FL_AC1

-HIGHB

+HIGHB

D+5V

SCPU+3.3V

A-12V

A+6.8V

A+12V

D+3.3V

3959_PWR

VCC_3959

AP6503

USB5V_ON

IC2008

MM3529A32PRE

RAQ045P01

Q2042

D+1.8V_ON

ST_H+5V

VCC_16315

Q702

FL-30V

NJM2831F33

123

4 5

IC2005

S-1170B50UC-OUJ

1 2 3

45

BA00DD0WHFP

IC2021

-

RAQ045P01

Q2026

H+3.3V_FETON

VIDEO PART

SA1117D-1.2V

IC2013

123

4 5

IC2006

S-1170B50UC-OUJ

6 7 8

A

B

C

D

5

6 7 8

VSX-523-K

E

F

13

1

A

I

L

REG ASSY

K

SMPS ASSY

H

INSEL ASSY

J

HPMIC ASSY

FL_FB

A+12V

FR_FB

FL_A

FV

FR_A

SMPS

C_FB

CEN_A

AC CORD

(TOP)

POWER TRANS

4.4 GND BLOCK DIAGRAM

A

2 3 4

B

C

D

E

F

14

1

2 3 4

VSX-523-K

5

A

MAIN ASSY

F

CPU ASSY

I

FRONT ASSY

G

AMP5 ASSY

ASSY

D

FUSB ASSY

B

D-MAIN ASSY

A+12V

FR_FB

A+12V

C_FB

SL_FB

+HIGHB1

A-12V

FV

FR_A

CV

A+12V

-HIGHB

C_FB

A+12V

SR_FB

CEN_A SL_ACEN_A

SUV

SR_A

DC_PROTECTION

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

15

1

No Power

Other trouble.

Check D41, D103, T101, IC102 on
SMPS Assy or replace SMPS Assy.

AMP DC Protention works.
Disconnect speaker cables if you connect speakers.
(Prevention of Speaker destruction.)

Is Stand by?

(or ON → Stand by)

Is the error indicated?

(HDMI LED flashing?)

Does DC Protection work

when power ON again?

Ye s

This is just for general reference and does not including every single case.

Ye s

Ye s

No

No

Replace SMPS Assy.

No

Check +5.6V line on D-MAIN Assy
or replace D-MAIN Assy.

Cancel the DC detection. Refer to "6. [3] 3.4 How to
cancel the status after detection of the DC error".

Connect speakers, and check that sound output does
not have any problem.

No

Check IC301 on CPU Assy or
replace CPU Assy.

Replace CPU Assy.

No

Check cable connection between CX101 on SMPS Assy
and CN101 on D-MAIN Assy. If it is OK, replace that cable.

No

Check connection betwwern CN201 on D-MAIN Assy
and CN201 on CPU Assy.

No

No

Is the fuse (F100) open?

Is the voltage +5.6 V?

(SMPS Assy CX101

pins 5, 6, 7)(C129 +side)

Is the voltage +5.6 V?

(D-MAIN Assy

CN101 pins 1, 2, 3)

Ye s

Ye s

Is the voltage +5.6 V?

(D-MAIN Assy

CN201 pins 3, 4)

Ye s

Is the voltage +5.6 V?

(CPU Assy

CN201 pins 30, 31)

Is the voltage +3.3 V?

(CPU Assy

IC301 pin 2)

Ye s

Ye s

Refer to "5.3 [1] Overload and DC Protection Circuit",
Diagnosis AMP5 Assy and MAIN Assy.

Ye s

No

No Power

2 3 4

5. DIAGNOSIS

5.1 TROUBLESHOOTING

A

B

C

D

E

F

16

VSX-523-K

1

2 3 4

5

No FL DISPLAY

Are the voltage 2.3 Vac to 2.5 Vac?

(FRONT Assy CP703 pins 1, 3)

This is just for general reference and does not including every single case.

Ye s

No

No

No

No No No

No

Replace Power transformer.

Replace FLT701 or
replace FRONT Assy.

Check Q17, R64, R65, R66, D23,
ZD24, ZD25 on MAIN Assy
or replace MAIN Assy.

Check FLT701, R779, R780 or
replace FRONT Assy.

Ye s

Check L701, IC701 or
replace FRONT Assy.

No

No

Check Q702, Q703, R777, R778 or
replace FRONT Assy.

Replace CP16.

No

Is the voltage -30 V?

(FRONT Assy C728 - side)

Is the voltage 3.3 V?

(FRONT Assy C730 + side)

Are the voltage 2.28 Vac?

(FRONT Assy FLT701

pins 1, 2, 38, 39)

Are the voltage -30 V?

(FRONT Assy CN704A

pins 3, 4)

Are the voltage -30 V?

(CPU Assy CN704B

pins 3, 4)

Are the voltage -30 V?

(CPU Assy CN209A

pins 21, 22)

Are the voltage -30 V?

(MAIN Assy CP16

pins 21, 22)

Is the voltage 2.27 Vac

to 2.28 Vac?

(Transformer orange wire)

Ye s

Replace FFC.

Replace FRONT Assy.

Replace FLT701.

Ye s

Ye s

Is damage in FLT701?

Ye s

Ye s

Replace CN209A or
replace CPU Assy.

Ye s

Ye s

No

No FL DISPLAY

6 7 8

A

B

C

D

5

VSX-523-K

6 7 8

E

F

17

1

A B C

No Sound

Phones

When connected phones,

is CN206 pin 4 (HP_DET)

low?

Is the voltage 0 to 12 V?

(CPU Assy R105)

Does the sound of speaker

front ch output?

Set "STEREO" mode with STANDARD

SURROUND key and speaker ON/OFF

with SPEAKERS key.

Is pin 18 voltage changing

from 3.3 V to 2.23 V?

(CPU Assy CP704B pin 18)

Change analog input signal to

another analog input (e.g VIDEO)

and select it.

Are the signal on AMP5 Assy

CP401 pin 1, 9?

Does HP OUTPUT signal

output?

(CPU Assy CN206 pin 1 or 3)

When connected phones,

does the relay change to phones?

(CPU Assy IC203 pin 24 0 → 3.3 V)

This is just for general reference and does not including every single case.

Speaker front ch sound

Relay Control Check flow

No

No

No

Replace HPMIC Assy.

Replace HPMIC Assy.

No Problem / No Damage

Replace HPMIC Assy.

Replacce Q102, Q103, R105 on
CPU Assy or replace CPU Assy.

Check IC701 on FRONT Assy
or replace FRONT Assy.

No

No

No No

Replacce Q2, Q9 on MAIN Assy
or replace MAIN Assy.

Check and repair FL or FR AMP
circuit or replace AMP5 Assy.

No

Replace CPU Assy.

No

No No

No

Check connectors between FRONT
Assy CN106 and HPMIC Assy CP104.

Replace CPU Assy.

No Problem / No Damage

Check connecters between CPU Assy
CN206 and FRONT Assy CN106.

Ye s

Ye s

Ye s

Ye s

Ye s

Ye s

Replace FFC between CP704B
and CN704A.

Ye s

Check the problem analog signal
line between input connector and
IC400 (Input selector IC)
or replace MAIN Assy.

Ye s

Ye s

Ye s

Ye s Ye s

No Sound

Is the voltage changing

3.3 V to 2.23 V?

(FRONT Assy CN704A pin 18)

Is the voltage 0 to 3.2 V?
(CPU Assy CN208 pin 6)

Is the voltage 0 to 12 V?

(MAIN Assy R20)

Analog in (e.g. CD)

Pure Direct →

Speaker out sound

Are the signal on AMP5

Assy CP401 pin 1, 9?

A

2 3 4

B

C

D

E

F

18

1

VSX-523-K

2 3 4

5

D E

A B C

Check the voltage.

(MAIN Assy W7 pin 10: +12 V)

(MAIN Assy W7 pin 13: -12 V)

Check the voltage.
(MAIN Assy W7 pin 10: +12 V)
(MAIN Assy W7 pin 13: -12 V)

Are the signal on CONCT

Assy CN110 pin 9, 11?

Are the signal on CONCT

Assy CN109 pin 5, 7?

Are the signals on CONCT

Assy CN109 pin 1, 3?

Are the signals on MAIN

Assy CP110 pin 1, 3?

Is Digital signal from OPT

(or COAX) input OK?

INPUT?

No

Auto Surround

Check between MAIN Assy CP110
and CONCT Assy CN110.

No

Check the data signals at the following locations.
VOL_CLK pin 7, VOL_DATA pin 8, CN208 (CPU Assy) - CP15 (MAIN Assy)

Check CP15 pin 7 (VOL_CLK),
pin 8 (VOL_DATA).

Repair IC400 and its peripheral
circuit or replace MAIN Assy.

Check and repair analog audio lines
between IC400 pin54, 55 and
CP110 pin1, 3 or replace MAIN Assy.

No

No

No

No

No

No

Is the digital signal

on D-MAIN Assy

CP2008 pin 1?

No

No

No

No

No

Analog

input

Digital

input

Replace MAIN Assy.

Replace CONCT Assy.

Replace CONCT Assy.

Replace OPTCO Assy.

No Problem / No Damage

Ye s

Ye s

Repair IC402, IC403 and its peripheral
circuit or replace MAIN Assy.

Repair IC2011 (AK4588) and its
peripheral circuit or replace D-MAIN Assy.

Check selection of speaker system
by [SPEAKERS] key on front panel
is correct.

Check signals of problem channel
on AMP5 Assy CP401 pin 3 (SL),
5(C), 7(SR).

Check signals of problem channel
on CONCT Assy CN110 pin 7 (SR),
5 (SL), 3 (C), 1 (SW).

No No

Check signals of problem channel
on CONCT Assy CN109 pin 9 (SR),
11 (SL),13 (C),15 (SW).

Check and repair AMP circuit of problem
channels or replace AMP5 Assy.

Check relay operating. (Refer to Relay
Control Check flow for Front ch.)

Ye s

Check signal line between
CN109 and CN110.

Ye s

Ye s

Ye s

Ye s

Ye s

Repair IC2011 (AK4588) and its
peripheral circuit or replace D-MAIN Assy.

Change speaker system to correct
setting.

Select surround mode to EX.STEREO
in Advanced Surround .

Check CPU Assy CN208 pin 4
(C_RLY) pin 5 (S_RLY).

No sound from Speaker System
is "SP: OFF" is selected,

Ye s

Ye s

Ye s

Ye s

Replace MAIN Assy
or their peripheral circuit.

Ye s

Check the signal CN109 - CN110
or replace CONCT Assy.

Ye s

Check +/- 12 V line on MAIN Assy
or replace MAIN Assy.

Ye s

Speaker C (SB etc) ch (Front LR is OK)

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

19

1

D E

Is Front L, R speaker output

sound OK?

Input PCM to COAX in or

OPT in, set Auto Surround

No

Repair IC2011 (AK4588) and its
peripheral circuit or replace D-MAIN Assy.

No

Replace IC2021, IC2024 on D-MAIN
Assy or replace FUSB Assy.

No

Repair IC2011 (AK4588) and its
peripheral circuit or replace D-MAIN Assy.

Check IC1200 on MAIN Assy or
replace MAIN Assy.

Repair IC2011 (AK4588) and its
peripheral circuit or replace D-MAIN Assy.

Replace D-MAIN Assy.

Replace PACK601 (Tuner Pack)
on MAIN Assy.

Ye s

Ye s

Repaier or Replace D-MAIN Assy.

Ye s

Tuner → (Other Analog OK)

USB in →

HDMI in on rear →

Composite in → No Composite out

Replace D-MAIN Assy.

Rear HDMI in → No HDMI out

Check IC1203, XTAL1200, XTAL1201,
Q1207, Q1208, Q1209 on MAIN Assy
or replace MAIN Assy.

No OSD

Is the voltage 5 V?

(D-MAIN Assy CP2006 pin 1,

pin 3, 4 digital signal)

A sound not coming out only

in HDMI IN1 to IN4?

No Picture

This is just for general reference and does not including every single case.

No Picture

A

2 3 4

B

C

D

E

F

20

VSX-523-K

1

2 3 4

5

Functional Name

iPod ERROR MESSAGE

Outline

Error message is displayed at abnormality time.

Basic Operation

Front Key Sequence Change OSD display Time (sec) FL Display

Over Current Error

I/U ERR4

No Track Caution

N OTRACK

5.2 USB/iPod ERROR MESSAGE

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

21

1

[1] Overload and DC Protection Circuit

CPU ASSY

F

AMP5 ASSY

G

MAIN ASSY

A

MAIN ASSY

A

REG ASSY

L

2 3 4

5.3 PROTECTION CIRCUIT

A

B

C

D

E

F

22

1

2 3 4

VSX-523-K

5

[2] TEMP Protection Circuit

CPU ASSY

F

AMP5 ASSY

G

AMP5 ASSY

G

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

23

1

(M3030RFGPFP_256K)(CPU ASSY: IC203)

MAIN CPU

• Pin Function

No. Symbol I/O Description

1 DIRECT_SEL O Not used
2CNT_LED O Not used
3 3959_RST O MFI IC reset signal
4 3959_PWR O MFI IC Power control pin
5POWERDOWN I Power down signal input pin
6 NC Not used
7 RMC I Remote control signal input pin
8 GND Ground

9CNVSS_UP I Switches processor mode
10 24C16_SDA I/O Data signal input & output for data backup of main CPU
11 24C16_SCL O Clock signal output for data backup of main CPU
12 RESET I CPU reset signal input pin (active at L)
13 XOUT O Output for 16 MHz Crystal
14 GND Ground
15 XIN I Input for 16 MHz Crystal
16 3V3 +3.3 V Power Supply
17 NMI Pull up
18 TUNER_INT I Tuner Interrupt signal input pin
19 4588_INT I AK4588 Interrupt signal input pin
20 WOL_NW I Not used
21 NC Not used
22 A_MUTE O Audio output control pins at Mute Tr (active at L)
23 HP_DET I Monitoring the input pin headphone connection
24 HP_RLY I Headphone audio output control pins at Mute Tr (active at L)
25 SW_SUM I Output for Sub Woofer SUMMING Control (H: SUMMING)
26 CTL_B O IC control signal B output pin for selecting the video input
27 NC Not used
28 OSD/FLT_CLK O OSD & FL drive IC output pin of the Clock
29 CTL_A O IC control signal A output pin for selecting the video input
30 MUTE_B+_CONT O Power control pin mute B+
31 U_TX O Output for Upgrade (UART)
32 U_RX I Input for Upgrade (UART)
33 BUSY_JTAG O BUSY signal output pin
34 SCLK_JTAG/TR_DET' I Serial clock input and Protection pin
35 VOL_DATA O Data signal output for R2A15219 (I2C)
36 VOL_CLK O CLK signal output for R2A15219 (I2C)
37 STBY_RLY O Output to ST-BY Relay ON/OFF (active at H)
38

OSD_RST O OSD IC Reset signal output pin

39

F_RLY O Tr driven control pins at the Front speaker output Relay (active at H)
40 TUNER_SCLK O Clock signal output for Tuner Pack
41 EPM_UP I UPGRADE
42 TUNER_SDIO I/O Data signal input & output for Tuner Pack
43 TUNER_SEN O Output for Tuner Pack Serial Enable Input (active at L)
44 TUNER_RST O Output to reset Tuner Pack (active at L)
45 NC Not used
46 OSD_CE/CE O OSD IC enable signal output and UPGRADE pin
47 NC Not used
48 S_RLY O Tr driven control pins at the Surround speaker output Relay (active at H)
49 3959_SDA I/O MFI IC DATA signal
50 3959_SCL I/O MFI IC CLK signal

2 3 4

5.4 IC INFORMATION

A

B

C

D

E

F

24

VSX-523-K

1

2 3 4

5

No. Symbol I/O Description

51 C_RLY O Tr driven control pins at the Center speaker output Relay (active at H)
52 NC Not used
53 SP_DC O HDMI LED on/off control pin if Speaker DC Protection
54 NET_PWR O Control pin HDMI IC +5 V REG. IC (on: H)
55 H+1.8V_ON O Control pin HDMI IC +1.8 V REG. IC (on: H)
56 D+3.3V_ON O Control pin digital +3.3V DC/DC IC (on: H)
57 MIC_DET O Monitoring the input pin microphone connection (detection: L)
58 4588_PDN O Output for AK4588 power down
59 4588_SDA I/O Data signal output for AK4588 (I2C)
60 4588_SCL O Clock signal output for AK4588 (I2C)
61 DSP_SIMO O Data signal Input for DA808
62 3V3 +3.3 V Power Supply
63 DSP_SPICLK O Clock signal output for DA808 (SPI)
64 GND Ground
65 DSP_RST O Output to reset DA808
66 NC Not used
67 DSP_SOMI I Data signal output for DA808 (SPI)
68 DSP_CS O Chip select signal output for DA808
69 DSP_ENABLE I SPI Enable signal input from DA808
70 HDMI_SEL O IC signal of the control pins at select HDMI or analog audio
71 PROTECT2 I AMP Assy input signal of the RADIATOR THERMAL pin (L = PROTECTION)
72 H+3.3V_FET_ON O Control pin HDMI IC +3.3 V REG. IC (on: H)
73

SUB_ON O Control pin sub CPU IC +3.3 V REG. IC (on: H)
74 SUB_IRQ I Interrupt signal output pin to main CPU
75 HDMI_MUTE I Input for HDMI_RX_MUTE condition
76 USB5V_ON O Output for NCP380 Enable Input
77 SUB_RST O Output to reset sub CPU
78 USB5V_DET O USB+5 Voltage monitor input pin overcurrent protection
79 SCDO_MAIN O Data signal output to sub CPU

80 CSCK_MAIN O Clock signal output for sub CPU
81 SET OPTION I Input for Set option
82 STEP OPTION I Input for Step (Group) option
83 VIDEO_MUTE O Ouput for Video IC MUTE condition
84 OSD/FLT_DATA O OSD or FLT Data pin
85 PROTECT1 I AMP Assy Protection detection signal input pin (ASO = 0.82 V, DC = 1.39 V)
86 VOL_DN I Data input for VOLUME encoder (VOLUME DOWN is counterclockwise direction)
87 VOL_UP I Data input for VOLUME encoder (VOLUME UP is clockwise direction)
88 IN_UP I Data input for INPUT selector encoder
89 NC Not used

90 KEY1 I Data input for Key1 scan
91 KEY3 I Data input for Key3 scan
92 KEY2 I Data input for Key2 scan
93 IN_DN I Data input for INPUT selector encoder
94 FLT_CE O Output for chip enable of SC16315
95 NC Not used
96 GND Ground
97 USBDCERR O Not used
98 3V3

+3.3 V Power Supply

99 3V3 +3.3 V Power Supply

100 V+5V_DET I Detection pin V+5V protection

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

25

1

(EPF025A)(D-MAIN ASSY: IC2001)

SUB CPU

• Pin Function

No. Symbol I/O Description

1 NC Not used
2 CSCK_MAIN I Clock signal input from main CPU
3 SCDO_MAIN I Data signal input from main CPU
4 HSCL I/O IIC clock signal output pin
5 HSDA I/O IIC data signal in/output pin
63V3 +3.3 V power supply
7 NC Not used
8 3V3 +3.3 V power supply

9GND Ground
10 NC Not used
11 NC Not used
12 3V3 +3.3 V power supply
13 NC Not used
14 NC Not used
15 SUB_RST I Sub CPU reset signal input pin
16 SUB_OPO I Chip operation mode select signal input pin (0: normal)
17 GND Ground
18NC Not used
19 NC Not used
20 NC Not used
21 NC Not used
22 D+1.2V_ON O Control pin DSP IC +1.2 V REG. IC (on: H)
23 D+1.8V_ON O Control pin DSP IC +1.8 V REG. IC (on: H)
24 NC Not used
25 NC Not used
26 NC Not used
27 NC Not used
28NC Not used
29

D+3.3V_FETON O Control pin DSP IC +3.3 V REG. IC (on: H)
30 D+5V_FETON O Control pin AK4588 IC +5 V REG. IC (on: H)
31 NC Not used
32 NC Not used
33 NC Not used
34 NC Not used
35 NC Not used
36 SUB_IRQ O Interrupt signal output pin to main CPU
37 THRU_LED O HDMI LED on/off control pin
38NC Not used
39 3V3 +3.3 V power supply
40 GND Ground
41 XIN I Input for 24 MHz Crystal
42 XO O output for 24 MHz Crystal
43 3V3 +3.3 V power supply
44 GND Ground
45 RSTb O Reset signal output pin to HDMI IC
46 NC Not used
47 NC Not used
48 3V3

+3.3 V power supply
49 HDMI_CEC I/O Data signal Input from HDMI_CEC
50 GND Ground
51 HT0_CTLB O Hot plug detect signal output pin (DVD FUNCTION)
52 HT1_CTLB O Hot plug detect signal output pin (SAT/CBL FUNCTION)
53 HT2_CTLB O Hot plug detect signal output pin (GAME FUNCTION)
54 HT3_CTLB O Hot plug detect signal output pin (BD FUNCTION)
55 NC Not used
56 NC Not used
57 NC Not used
58 INTb I interrupt signal input pin from EP9442
59 NC Not used
60 HPD_IN I Intput for HDMIOUT HPD
61 NC Not used
62 SUB_RXD I Soft update UART comunication data input pin (UPDATE JIG B'D)
63 SUB_TXD O Soft update UART comunication data output pin (UPDATE JIG B'D)
64 HDMI_CEC I/O Data signal Input from HDMI_CEC

A

2 3 4

B

C

D

E

F

26

1

VSX-523-K

2 3 4

5

[1] Display mode for numbers of protection detections

[Purpose]

[Basic operations]

FL Display Description of IndicationsKey Operation

(STANDBY state)

[PRESET k] +
[STANDBY/ON] keys
(Initial display)

[ENTER] key

[ENTER] key

[ENTER] key

(Initial display)

5 (-> normal) *1

5 (-> normal) *1

5 (-> normal) *1

Number of DC error detections

Number of OVERLOAD error detections

Number of abnormal-temperature

error detections

5 (-> normal) *1 Number of abnormal-temperature

error detections

Time (sec.)

The numbers of detections for various protection processes are displayed.

*1 "5 (-> normal)" denotes that the display will return to the normal indication when no key operation is performed
for 5 seconds.
*2 Variable range: 0 to 255

[How to enter/exit]

During Standby mode, simultaneously press and hold the [PRESET k] and [STANDBY/ON] keys for 2 seconds to enter
this mode.
The display will return to the normal indication when no key operation is performed for 5 seconds.

Counter

Counter

*2

*2

Counter

Counter

*2

The above-mentioned Display mode is available only when the product operates properly.

If any protection function is activated while the product is in use, the product cannot be turned ON and enter the above
Display mode. In such a case, cancel the protection function, referring to “[3] 3.4 How to cancel the status after detection of the
DC error." If a protection function is activated immediately after the previous protection function is canceled, cancel that
protection function again then enter STBY mode immediately. You can then see the error logs, following the above procedures,
until a next protection function is activated.

*2

6 7 8

6. SERVICE MODE

A

B

C

D

VSX-523-K

5

6 7 8

E

F

27

1

[2] Reset mode for numbers of protection detections

[Purpose]

[Basic operations]

FL Display Description of IndicationsKey Operation

(STANDBY state)

[ALC/STANDARD SURR]
+ [STANDBY/ON] keys
(press and hold the keys
for 10 seconds.)

(Counter Clear end)

[ENTER] key

(Normal display)

5 (-> normal) *1

5 (-> normal) *1

usually

*2

Time (sec.)

For clearing all the counts of protection detections.
(This mode resets the counts of protection detections.)

1. When the procedures for Reset mode for numbers of protection detections are completed, all the counters will be
reset to "000."

2. Prohibitions:
The protection detection counts cannot be cleared (reset to 000) with the MEMORY CLEAR process.
They can only be cleared when the procedures of Reset mode are completed.

*1 "5 (-> normal)" denotes that the display will return to the normal indication when no key operation is performed
for 5 seconds.
*2 Indication when the BD function is selected

[How to enter/exit]

During Standby mode, simultaneously press and hold the [ALC/STANDARD SURR] and [STANDBY/ON] keys
for 10 seconds to enter this mode.
The display will return to the normal indication when no key operation is performed for 5 seconds.

[Detailed explanations]

A

2 3 4

B

C

D

E

F

28

1

2 3 4

VSX-523-K

5

[3]

The unit’s operation when a error is detected

[Purpose]

[Basic operations]

FL Display Description of IndicationsKey Operation

3.1 DC (AMP is abnormality) error detection

(Normal display)

(DC detection)

(Auto)

(RECEIVER POWER OFF)

usually

Normal display

Time (sec.)

• The unit’s operation when a DC/OVER/TEMP error is detected is described here.

• How to cancel the status after detection of a DC error is described here, because no key input will be accepted after
a DC error detection.

FL Display Description of IndicationsKey Operation

3.2 OVERLOAD (overcurrent) error detection

(Normal display)

(OVERLOAD detection)

(Auto)

(RECEIVER POWER OFF)

usually

Normal display

Time (sec.)

If the AC power cord is plugged in while the AVR is prohibited from being ON because of DC detection, the HDMI LED will
flash at intervals of 500 msec.

6 7 8

A

B

C

D

E

F

VSX-523-K

5

6 7 8

29

1

Simultaneously holding the [ADVANCD SURROUND] and [STANDBY/ON] keys on the
front panel pressed for 2 seconds will cancel Key Input Inhibition mode after a DC error
detection and turn the unit ON.

[Detailed explanations]

3.3 TEMP (AMP overheat) error detection

For detection of a TEMP error, the unit monitors both the TR_DET and PROTECT2 signals. If a TEMP error is detected,
the processes shown below will be performed. The processes shown below are rough operational specifications and are
not the actual commands from the mounted components.
After a TEMP error is detected, the count of protection activation detections will be updated.

FL Display Description of IndicationsKey Operation

3.4 How to cancel the status after detection of the DC error

(STANDBY state)

(Normal display)

usually

Normal display

Time (sec.)

[ADVANCED SURROUND]
+ [STANDBY/ON] keys
(press and hold the keys
for 2 seconds.)

Counter: Temp2

TR_DET
P6_4 (34 pin)
(TRTHER_DET from AMP Assy)

Normal Operations

Deduct 3 from the current VOL
value. Have "TEMP" flashing
on the FL display for 3 sec.

POWER OFF (STBY)

*1

*1: The detection interval must be 1 sec or less.
*2: If PROTECT 2 is detected while TR_DET detection
is prohibited for 2 min, the PROTECT 2 function will
be activated.

Prohibit detection of
TR_DET for 2 min.
*2

Is TR_DET detected?

Is the VOL value 5

or less?

No

No

No

Ye s

Ye s

Ye s

Detection of TR_DET

is resumed after 2 min.

Is TR_DET detected?

Counter: Temp1

PROTECT2
PL2_1 (71 pin)
(RADI_DET from AMP Assy)

Normal Operations

MUTE ON and ALL Speakers/
Phones Relay are set to OFF.
Have "OVERHEAT" flashing
on the FL display for 3 sec.

*3

*3: The detection interval must be 1 sec or less.

Timer START is performed
for 3 sec.

PROTECT2 detected?

No

No

Ye s

Ye s

After 3 sec,

PROTECT 2 is rechecked.

Is PROTECT 2 detected?

POWER OFF (STBY)

A

2 3 4

B

C

D

E

F

30

1

VSX-523-K

2 3 4