JVC RX-8040B User manual

SERVICE MANUAL
COPYRIGHT © 2004 Victor Company of Japan, Limited No.MB303
2004/7
AUDIO/VIDEO CONTROL RECEIVER
MB30320047
RX-8040B
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Area suffix
UJ ---------------------- U.S.Military

1-2 (No.MB303)
SPECIFICATION
*1: Measured on AC 110 V, 127 V, 220 V and 240 V
*2: Corresponding to Linear PCM, Dolby Digital, and DTS (with sampling frequency -32 kHz, 44.1 kHz, 48 kHz).
Designs & specifications are subject to change without notice.
Amplifier
Output Power At Stereo Operation Front Channel 100 W*1 per channel, min. RMS, driven into 8 Ωat 1 kHz with no more than 0.8% total
harmonic distortion (IEC268-3/DIN).
At Surround Opera-
tion
Front Channel 100 W*1 per channel, min. RMS, driven into 8 Ωat 1 kHz, with no more than 0.8% total
harmonic distortion.
Center Channel 100 W*1, min. RMS, driven into 8 Ωat 1 kHz, with no more than 0.8% total harmonic
distortion.
Surround Channel 100 W*1 per channel, min. RMS, driven into 8 Ωat 1 kHz, with no more than 0.8% total
harmonic distortion.
Surround Back Channel 100 W*1, min. RMS, driven into 8 Ωat 1 kHz, with no more than 0.8% total harmonic
distortion.
Audio Audio Input Sensitivity/Impedance (1 kHz) DVD IN, VCR 1 IN, VCR 2 IN, TV SOUND/DBS IN, VIDEO:200 mV/47 kΩ
TAPE/MD IN, CDR IN, CD IN:200 mV/47 kΩ
PHONO IN (MM):2.5 mV/47 kΩ
Audio Input (DIGI-
TAL IN)*2
Coaxial DIGITAL 1 (DVD):0.5 V(p-p)/75 Ω
Optical DIGITAL 2 (CD), DIGITAL 3 (TV), DIGITAL 4 (CDR):-21 dBm to -15 dBm (660 nm ±30
nm)
Audio Output Level ZONE 2 PREOUT:1 V
PREOUT:1 V
Recording Output Level TAPE/MD OUT, CDR OUT, VCR 1 OUT, VCR 2 OUT:200 mV
Digital Output (DIGITAL OUT):Optical Signal wave length:660 nm
Output level:-21 dBm to -15 dBm
Signal-to-Noise Ratio ('66 IHF/'78 IHF) DVD IN, VCR 1 IN, VCR 2 IN, TV SOUND/DBS IN, VIDEO:87 dB/80 dB
TAPE/MD IN, CDR IN, CD IN:87 dB/80 dB
PHONO IN (MM):70 dB/78 dB at OUT (REC)
Frequency Response (8 Ω) DVD IN, VCR 1 IN, VCR 2 IN, TV SOUND/DBS IN, VIDEO:20 Hz to 100 kHz (+1 dB, -
3 dB)
TAPE/MD IN, CDR IN, CD IN:20 Hz to 100 kHz (+1 dB, -3 dB)
PHONO IN (MM):20 Hz to 20 kHz (±1 dB)
RIAA Phono Equalization ±1.0 dB (20 Hz to 20 kHz)
Bass Boost +6 dB ±1.0 dB at 100 Hz
Equalization 63 Hz, 250 Hz, 1 kHz, 4 kHz, 16 kHz: ±8 dB (in 2 dB steps)
Video Video Input Sensitivity/Impedance Composite Video:DVD IN, TV SOUND/
DBS IN, VCR 1 IN, VCR 2 IN, VIDEO
1 V(p-p)/75 Ω
S-video:DVD IN, TV SOUND/DBS IN, VCR
1 IN, VCR 2 IN, VIDEO
(Y: luminance):1 V(p-p)/75 Ω
(C: chrominance, burst):0.286 V(p-p)/75 Ω
Component Video :DVD IN, DBS (VCR 1)
IN
(Y: luminance):1 V(p-p)/75 Ω
(PB/PR):0.7 V(p-p)/75 Ω
Video Output Level Composite Video:VCR 1 OUT, VCR 2
OUT, MONITOR OUT
1 V(p-p)/75 Ω
S-video:VCR 1 OUT, VCR 2 OUT, MONI-
TOR OUT
(Y: luminance):1 V(p-p)/75 Ω
(C: chrominance, burst):0.286 V(p-p)/75 Ω
Composite Video:MONITOR OUT (Y: luminance):1 V(p-p)/75 Ω
(PB/PR):0.7 V(p-p)/75 Ω
Synchronization Negative
Signal-to-Noise Ratio 45 dB
FM tuner (IHF)
Tuning Range 87.50 MHz to 108.00 MHz
Usable Sensitivity Monaural 12.8 dBf (1.2 µV/75 Ω)
50 dB Quieting Sensitivity Monaural 16.0 dBf (1.7 µV/75 Ω)
Stereo 37.5 dBf (20.5 µV/75 Ω)
Stereo Separation at OUT (REC) 35 dB at 1 kHz
AM tuner
Tuning Range 531 kHz to 1 602 kHz (at 9 kHz intervals)
530 kHz to 1 600 kHz (at 10 kHz intervals)
General
Power Requirements AC 110 V/127 V/220 V/230 V - 240 V , adjustable with the voltage selector, 50 Hz/60 Hz
Power Consumption 220 W (at operation) 6.0 W (in standby mode)
Dimensions (W ×H ×D) 435 mm ×157 mm ×425 mm
Mass 12.4 kg

(No.MB303)1-3
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of this product contains special hardware and
many circuits and components specially for safety purpos-
es. For continued protection, no changes should be made
to the original design unless authorized in writing by the
manufacturer. Replacement parts must be identical to
those used in the original circuits. Services should be per-
formed by qualified personnel only.
(2) Alterations of the design or circuitry of the product should
not be made. Any design alterations of the product should
not be made. Any design alterations or additions will void
the manufacturers warranty and will further relieve the
manufacture of responsibility for personal injury or property
damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteris-
tics are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by us-
ing replacement components rated for higher voltage, watt-
age, etc. Replacement parts which have these special
safety characteristics are identified in the Parts List of Ser-
vice Manual. Electrical components having such features
are identified by shading on the schematics and by ( ) on
the Parts List in the Service Manual. The use of a substitute
replacement which does not have the same safety charac-
teristics as the recommended replacement parts shown in
the Parts List of Service Manual may create shock, fire, or
other hazards.
(4) The leads in the products are routed and dressed with ties,
clamps, tubings, barriers and the like to be separated from
live parts, high temperature parts, moving parts and/or
sharp edges for the prevention of electric shock and fire
hazard. When service is required, the original lead routing
and dress should be observed, and it should be confirmed
that they have been returned to normal, after reassem-
bling.
(5) Leakage shock hazard testing
After reassembling the product, always perform an isola-
tion check on the exposed metal parts of the product (an-
tenna terminals, knobs, metal cabinet, screw heads,
headphone jack, control shafts, etc.) to be sure the product
is safe to operate without danger of electrical shock.Do not
use a line isolation transformer during this check.
• Plug the AC line cord directly into the AC outlet. Using a
"Leakage Current Tester", measure the leakage current
from each exposed metal parts of the cabinet, particular-
ly any exposed metal part having a return path to the
chassis, to a known good earth ground. Any leakage cur-
rent must not exceed 0.5mA AC (r.m.s.).
• Alternate check method
Plug the AC line cord directly into the AC outlet. Use an
AC voltmeter having, 1,000Ωper volt or more sensitivity
in the following manner. Connect a 1,500Ω10W resistor
paralleled by a 0.15µF AC-type capacitor between an ex-
posed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
voltmeter.
Move the resistor connection to each exposed metal
part, particularly any exposed metal part having a return
path to the chassis, and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and
repeat each measurement. Voltage measured any must
not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).
1.2 Warning
(1) This equipment has been designed and manufactured to
meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that
these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant
safety standards.
(4) It is essential that safety critical components are replaced
by approved parts.
(5) If mains voltage selector is provided, check setting for local
voltage.
1.3 Caution
Burrs formed during molding may be left over on some parts
of the chassis.
Therefore, pay attention to such burrs in the case of pre-
forming repair of this system.
1.4 Critical parts for safety
In regard with component parts appearing on the silk-screen
printed side (parts side) of the PWB diagrams, the parts that are
printed over with black such as the resistor ( ), diode ( )
and ICP ( ) or identified by the " " mark nearby are critical
for safety. When replacing them, be sure to use the parts of the
same type and rating as specified by the manufacturer.
(This regulation dose not Except the J and C version)
Good earth ground
Place this
probe on
each exposed
metal part.
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W
0.15 F AC TYPE

1-4 (No.MB303)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB303)1-5
SECTION 3
DISASSEMBLY
3.1 Removing the top cover
(See Fig.1)
(1) From the both sides of the main body, remove the four
screws Aattaching the top cover.
(2) From the back side of the main body, remove the three
screws Battaching the top cover.
(3) Remove the top cover in the direction of the arrow 2 while
extending the lower sections of the top cover in the direc-
tion of the arrow 1.
Fig.1
3.2 Removing the rear panel
(See Fig.2)
• Prior to performing the following procedures, remove the top
cover.
(1) From the back side of the main body, remove the strain re-
lief from the rear panel in the direction of the arrow.
(2) Remove the three screws C, thirty-five screws D, two
screws E, two screws Fand nut aattaching the rear panel.
3.3 Removing the RF unit and compu board
(See Figs.2 and 3)
• Prior to performing the following procedures, remove the top
cover.
(1) From the top side of the main body, cut off the tie band.
(See Fig.3)
(2) Disconnect the wire from the connector CN1 on the RF
unit. (See Fig.3)
(3) From the back side of the main body, remove the nut aat-
taching the RF unit. (See Fig.2)
(4) From the top side of the main body, disconnect the wire
from the connector CN262 on the relay board. (See Fig.3)
(5) From the back side of the main body, remove the two
screws Fattaching the compu board. (See Fig.2)
Fig.2
Fig.3
Top cover
A
2
1
1
B
A
C
Strain relief
C
Rear panel
D
C
D
DE D
D
F
Nut a
CN262
Relay board
CN1
Compu board
RF unit
Tie band

1-6 (No.MB303)
3.4 Removing the I/O board
(See Fig.4)
• Prior to performing the following procedures, remove the top
cover and rear panel.
(1) From the top side of the main body, remove the two plastic
rivets in the direction of the arrow 1, and remove the stop-
per boards in the direction of the arrow 2.
(2) Cut off the tie bands bundling the wires.
(3) Disconnect the wire from the connector CN722 on the cen-
ter board.
(4) Disconnect the wire from the connector CN714 on the front
board (L).
(5) Disconnect the wire from the connector CN717 on the sur-
round back board.
(6) Disconnect the wire from the connector CN719 on the front
board (R).
(7) Disconnect the wire from the connector CN723 on the main
board.
(8) Disconnect the I/O board from the connectors (CN205,
CN361, CN381 and CN501) in an upward direction.
Fig.4
1
2
2
CN381
CN205
CN501
Plastic rivet
Plastic
rivet
Stopper
board
Stopper board
Tie
band
Center boardFront board(L)Surround back board
Front
board(R)
CN719
CN717 CN714
CN722
CN723
Main
board
I/O board
1
CN361
Tie
bands

(No.MB303)1-7
3.5 Removing the front panel assembly
(See Figs.5 and 6)
• Prior to performing the following procedures, remove the top
cover, rear panel and I/O board.
(1) From the top side of the main body, remove the tie bands
bundling the wires. (See Fig.5)
(2) Disconnect the wire from the connector CN599 on the DSP
board. (See Fig.5)
(3) Disconnect the wire from the connector CN415 on the
audio2 board. (See Fig.5)
(4) Disconnect the wire from the connector CN206 on the vid-
eo board. (See Fig.5)
(5) Disconnect the wire from the connector CN244 on the S-
Video board. (See Fig.5)
(6) Disconnect the card wire from connector CN402 on the
power supply board. (See Fig.5)
(7) Disconnect the card wire from connector CN400 on the mi-
con board. (See Fig.5)
(8) Remove the tie band and wire protection board fixing the
card wire. (See Fig.5)
(9) Remove the two screws G, screws G' and screw Hattach-
ing the front panel assembly. (See Fig.5)
(10) From the bottom side of the main body, remove the four
screws Jattaching the front panel assembly. (See Fig.6)
(11) Remove the front panel assembly in the direction of the ar-
row. (See Fig.6)
Reference:
When attaching the screw G' and screw H, attach the earth
wire with it.
Fig.5
Fig.6
G' GG
H
Front panel assembly Earth wire
Earth wire
CN402
Power
supply
board
Tie
band
Tie
band
Micon
board
CN244
S-Video boardVideo board
CN206CN415
Audio2 board
CN599
DSP
board
CN400
Tie
band
Card
wire
Tie
band
Wire
protection
board
JJ
Front panel assembly

1-8 (No.MB303)
3.6 Removing the tuner, DSP board, Audio board, Audio2 board, Video board and S-Video board
(See Fig.7)
• Prior to performing the following procedures, remove the top
cover, rear panel and I/O board.
(1) From the top side of the main body, cut off the tie band bun-
dling the wire.
(2) Disconnect the card wire from connector CN314 on the au-
dio board, and take out the tuner.
(3) Disconnect the wire from the connector CN599 on the DSP
board.
(4) Disconnect the DSP board from the connector CN601 on
the micon board, and take out the DSP board.
(5) Disconnect the audio board from the connectors (CN101
and CN303) on the micon board, and take out the audio
board.
(6) Disconnect the wire from the connector CN415 on the
audio2 board.
(7) Disconnect the audio2 board from the connector CN301 on
the micon board, and take out the audio2 board.
(8) Disconnect the wire from the connector CN206 on the vid-
eo board.
(9) Disconnect the video board from the connector CN201 on
the micon board, and take out the video board.
(10) Disconnect the wire from the connector CN244 on the S-
Video board.
(11) Disconnect the S-Video board from the connector CN241
on the micon board, and take out the S-Video board.
Fig.7
3.7 Removing the micon board
(See Fig.8)
• Prior to performing the following procedures, remove the top
cover, rear panel, I/O board, tuner, DSP board, Audio board,
Audio2 board, Video board and S-Video board.
(1) From the top side of the main body, disconnect the card
wire from the connector CN400 on the micon board.
(2) Disconnect the relay board from the connector CN81 on
the micon board.
(3) Disconnect the parallel wire from the connectors (CN931
and CN932) on the micon board.
(4) Disconnect the parallel wire from the connector CN831 on
the main board.
(5) Remove the three screws Kattaching the micon board.
(6) Remove the three screws Lattaching the transistors
(Q921, Q931, and Q941) to the chassis base.
(7) Loosen the screw Mattaching the micon board.
Fig.8
CN314
Tuner
Audio board
Card wire
CN601
DSP
board
CN303
Tie
band
CN101
Video board
S-video board
CN206 CN244
Micon board
CN415
A
udio2 board
CN599
CN301
CN201 CN241
CN400
Micon
board
Relay
board
CN81
Card
wire
CN931 CN932
K
K
K
L
Transistors
(Q921,Q931,Q941)
Chassis base
M
CN831 Main board

(No.MB303)1-9
3.8 Removing the speaker board
(See Fig.9)
• Prior to performing the following procedures, remove the top
cover, rear panel.
(1) From the top side of the main body, remove the tie band
bundling the wires.
(2) Disconnect the wires from the connectors (CN813 and
CN814) on the main board.
(3) Disconnect the parallel wire from the connectors (CN931
and CN932) on the micon board.
(4) Take out the speaker board in the direction of the arrow.
Fig.9
3.9 Removing the relay board and main board
(See Fig.10)
• Prior to performing the following procedures, remove the top
cover.
(1) From the top side of the main body, remove the tie bands
bundling the card wire and wires.
(2) Remove the tie band and wire protection board bundling
the card wire.
(3) Disconnect the wire from the connector CN811 on the pow-
er transformer board 1.
(4) Disconnect the relay board from the connectors (CN71 and
CN81) on the power supply board and micon board.
(5) Disconnect the wire from the connector CN262 on the relay
board, and take out this board.
(6) Disconnect the wires from the connectors (CN723, CN813,
CN814, CN831 and CN881) on the main board.
(7) Disconnect the wire from the connector CN722 on the cen-
ter board.
(8) Disconnect the wire from the connector CN714 on the front
board (L).
(9) Disconnect the wire from the connector CN717 on the sur-
round back board.
(10) Disconnect the wire from the connector CN719 on the front
board (R).
(11) Remove the screw M, six screws Nand two screws Pat-
taching the main board.
(12) Take out the main board. Fig.10
Tie band
CN813
Main board
Speaker board
CN814
CN931 CN932
Micon board
Tie band
Wire
protection
board
Micon
board
Card wire
Tie bands
CN811
Power
transforme
r
board 1
CN71
CN81
Relay
board
Power
supply
board
CN831
CN881
Main
board
Tie
band
CN723
CN814
CN813
Center board
CN722
Front board(L)
CN714
Surround back board
CN717
Front board(R)
CN719
M
P
P
N
N
N
Tie band
CN262

1-10 (No.MB303)
3.10 Removing the heat sink
(See Figs.11 and 12)
• Prior to performing the following procedures, remove the top
cover and main board.
(1) From the reverse side of the main board, remove the two
screws Qattaching the main board to the heat sink. (See
Fig.11)
(2) Disconnect the connectors (CN701 to CN706) on the main
board, and remove the main board. (See Fig.11)
(3) Remove the twelve screws Rattaching the heat sink. (See
Fig.12)
3.11 Removing the center board, front boards (L/R), sur-
round boards (L/R) and surround back board
(See Figs.11 and 13)
• Prior to performing the following procedures, remove the top
cover and main board.
(1) From the reverse side of the main board, remove the two
screws Qattaching the main board to the heat sink. (See
Fig.11)
(2) Disconnect the connectors (CN701 to CN706) on the main
board, and remove the main board. (See Fig.11)
(3) Remove the two screws Rattaching the center board. (See
Fig.13)
(4) Remove the two screws Rattaching the front board (L).
(See Fig.13)
(5) Remove the two screws Rattaching the surround back
board. (See Fig.13)
(6) Remove the two screws Rattaching the front board (R).
(See Fig.13)
(7) Remove the two screws Rattaching the surround board
(L). (See Fig.13)
(8) Remove the two screws Rattaching the surround board
(R). (See Fig.13)
Fig.11
Fig.12
Fig.13
Heat sink Main board
CN703 CN701 CN704 CN702 CN705 CN706
QQ
Heat sink R
R
Surround board(R)
R R R R R R
Surround board(L)
Front board(R)
Surround back board
Front board(L)
Center board

(No.MB303)1-11
3.12 Removing the voltage selector board
(See Fig.14 and 15)
• Prior to performing the following procedures, remove the top
cover.
(1) From the back side of the main body, remove the two
screws Sattaching the voltage board. (See Fig.14)
(2) Remove the solders from the soldered sections bon the
power transformer board 2 and remove the wires of the
voltage selector board. (See Fig.15)
(3) Take out the voltage selector board.
Fig.14
Fig.15
Rear panel S
Power
transforme
r
board 2
Soldered sections b
Voltage
selector
board
Tie bands

1-12 (No.MB303)
3.13 Removing the power transformer
(See Fig.16)
• Prior to performing the following procedures, remove the top
cover.
(1) From the top side of the main body, remove the tie band
bundling the wires.
(2) Disconnect the wire from the connectors (CN55 and
CN811) on the power transformer board 1.
(3) Remove the solders from the soldered sections con the
power transformer board 2.
(4) Remove the four screws Tattaching the power transform-
er.
3.14 Removing the power/fuse board
(See Fig.16)
• Prior to performing the following procedures, remove the top
cover.
(1) From the back side and top side of the main body, remove
the tie band from the bundling the wires and the power
cord.
(2) Remove the screw Uand screw Vattaching the power/fuse
board.
(3) Remove the solders from the soldered sections dattaching
the power cord.
(4) From the reverse side of the power/fuse board, remove the
solders from the soldered sections eattaching the wires.
Fig.16
Tie band
Tie band
Tie band
CN811 CN55
Power
transforme
r
board 1
Power
transformer
board 2
Soldered
sections c
TT
Power
transforme
r
U
V
Power/fuse board
Soldered
sections d
Power cord
Soldered sections e

(No.MB303)1-13
3.15 Removing the power supply board
(See Fig.17)
• Prior to performing the following procedures, remove the top
cover.
(1) From the top side of the main body, disconnect the parallel
wire from the connector CN55 on the power transformer
board 1.
(2) Disconnect the card wire from the connector CN402 on the
power supply board.
(3) Disconnect the relay board from the connector CN71 on
the power supply board.
(4) Remove the three screws Wattaching the power supply
board.
(5) Remove the power supply board from the hook fof the
chassis base bracket in the direction of the arrow, and take
out the power supply board.
(6) Turn over the power supply board, and remove the solders
from the soldered sections gattaching the wire.
3.16 Removing the headphone jack board
(See Figs.17 and 18)
• Prior to performing the following procedures, remove the top
cover, rear panel, I/O board and front panel assembly.
(1) From the top side of the main body, disconnect the parallel
wire from the connector CN881 on the main board. (See
Fig.17)
(2) From the front side of the main body, remove the nut hand
screw Xattaching the headphone bracket to the front
bracket. (See Fig.18)
(3) Remove the three screws Wattaching the power supply
board. (See Fig.17)
(4) Take out the headphone jack board from the inside of the
chassis base while lifting the power supply board.
Fig.17
Fig.18
3.17 Removing the switch board
(See Fig.19)
• Prior to performing the following procedures, remove the top
cover, rear panel, I/O board and front panel assembly.
(1) From the back side of the front panel assembly, remove the
two screws Yattaching the switch board.
(2) Take out the switch board, and disconnect the wire from
the connector CN432 on the switch board.
3.18 Removing the power switch board
(See Fig.19)
• Prior to performing the following procedures, remove the top
cover, rear panel, I/O board and front panel assembly.
(1) From the back side of the front panel assembly, remove the
two screws Zattaching the power switch board.
(2) Take out the power switch board, and disconnect the wire
from the connector CN430 on the power switch board.
Fig.19
CN55
Power
transforme
r
board 1
Hook f
W
Relay board
Tie band
CN402
Card wirePower supply board
CN71
W
W
Soldered
sections g
Headphone
jack board
CN881
Main board
Nut h
Headphone jack board
Headphone bracket Front bracket
X
CN432 Y
Y
Switch board
Front panel assembly CN430
Power switch board
Front video board
Z

1-14 (No.MB303)
3.19 Removing the front key & system control board, front video board
(See Figs.20 to 23)
• Prior to performing the following procedures, remove the top
cover, rear panel, I/O board, front panel assembly, switch
board and power switch board.
(1) From the front side of the front panel assembly, pull out the
volume and jog knobs, and remove the nut iattaching the
front key & system control board. (See Fig.20)
(2) From the back side of the front panel assembly, remove the
eight screws AA attaching the sub panel assembly. (See
Fig.21)
(3) Remove the wires of the front video board from the hook j
of the front panel assembly in the direction of the arrow 1.
(See Fig.21)
(4) Remove the sub panel assembly while releasing the four
claws kin the direction of the arrow 2. (See Figs.21 and 22)
(5) From the front side of the front panel assembly, disconnect
the wire from the connector CN412 on the front key & sys-
tem control board, and take out the front video board. (See
Fig.23)
(6) Remove the claws mattaching the front key & system con-
trol board in the direction of the arrow and take out the front
key & system control board. (See Fig.23)
Fig.20
Fig.21
Fig.22
Fig.23
Volume knob
Nut i
Front panel assembly
Jog knob
AA
AA
Claw kClaw kClaw k
Hook j
Front panel assembly
Sub panel assembly
Front video board
2
2
1
2
2
Claw k
Sub panel assembly Front panel assembly
Front key & System control board
Front video board
Front panel assembly
Claw mClaw mCN412

(No.MB303)1-15
SECTION 4
ADJUSTMENT
4.1 Test mode
(1) Unplug the power plug.
(2) Insert power plug into outlet while pressing both "PRESET UP" key and "MIDLIGHT" key of the main body.
(3) Then, all segment of the FL display is blinking for 5 seconds, and tuner AM step is switching 9kHz.
(4) The high-speed of volume is checked by remote controller in the test mode.
(5) To release test mode, press "STANDBY/ON" key of the main body.
NOTE:
In the test mode, standby-LED is blinking for every 1 second.
4.2 Power amplifier section
Adjustment of idling current
Attention
This adjustment does not obtain a correct adjustment value immediately after the amplifier is used (state that an internal
temperature has risen).
Please adjust, after you turn off amplifier and internal temperature falls.
< Adjustment method >
(1) Set the volume control to minimum during this adjustment. (No signal & No load)
(2) Set the surround mode OFF.
(3) Turn VR787 and VR788 fully counterclockwise to warm up before adjustment.
If the heat sink is already warm from previous use the correct adjustment can not be made.
(4) For L-ch, connect a DC voltmeter between B2204 and B2205 (Lch) and, connect it between B2213 and B2214 (Rch).
(5) 30 minutes later after power on, adjust VR787 for Lch, or VR788 for Rch so that the DC voltmeter value has 1mV to 10mV.
* It is not abnormal though the idling current might not become 0mA even if it is finished to turn variable
resistance (VR787, VR788) in the direction of counterclockwise.
Measurement location B2204-B2205 (Lch) , B2213-B2214 (Rch)
Adjustment part VR787 (Lch) , VR788(Rch)
Front board (L)
VR788
Front board (R)
VR787
B2204 B2205
B2213 B2214
VR787 (Lch)
B2204, B2205 (Lch)
VR788 (Rch)
B2213, B2214 (Rch)

1-16 (No.MB303)
SECTION 5
TROUBLESHOOTING
5.1 Self-diagnose function
This model incorporates the following self-diagnostic functions.
5.1.1 Starting of self-diagnostic mode
• Insert power plug into outlet while pressing both "PRESET UP" key and "INPUT ANALOG" key of the main body.
Then, "Self-diagnostic mode" starts.
5.1.2 Displaying of state
• When "Self-diagnostic mode" starts, system Micon version is displayed on the FL display.
Each turning MULTI JOG of the main body in the mode changes a state as follows.
FL display (Code)
S0001
D01
D02
D3
D4
D5
D6
D7
FL display State
2004030840
00.00.17
04/02/20
DspRev08
ANALOG02
Fs48kHz
PCM
2/0.0
System Micon version
DSP Micon version
Changed date of version
DSP version
Setting information
Setting information
Setting information
Channel information
Multi JOG
Preset up keyInput analog key
FL display

(No.MB303)1-17

(No.MB303)
AV & MULTIMEDIA COMPANY AUDIO/VIDEO SYSTEMS CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
Victor Company of Japan, Limited
WPC
Printed in Japan

SCHEMATIC DIAGRAMS
No.MB303SCH
2004/7
RX-8040B
Contents
Block diagram
Standard schematic diagrams
Printed circuit boards
2-1
2-2 to 11
2-12 to 20
CD-ROM No.SML200407
AUDIO/VIDEO CONTROL RECEIVER
COPYRIGHT 2004 Victor Company of Japan, Limited.
Area suffix
UJ ---------------------- U.S.Military

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the
parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " "
mark nearby are critical for safety.