JVC RV-B550BU User manual

SERVICE MANUAL
CD PORTABLE SYSTEM
No.20826C
Jan. 2001
COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.
RV-B550BU
RV-B550BU
Area Suffix
Contents
Safety precautions ...................................1-2
Importance administering
point on the safety .............1-3
Important for laser products .................... 1-4
Preventing static electricity ......................1-5
Disassembly method ............................... 1-6
Adjustment method ................................. 1-15
Flow of functional operation
until TOC read ................. 1-19
Maintenance of laser pickup ....................1-20
Replacement of laser pickup ....................1-20
Description of major ICs .......................... 1-21~29
UY ................ Argentina
This service manual adds UY version to the service manual
(RV-B550BU No.20826) previously issued.
This service manual is made from 100% recycled paper.
SLEEP
CLOCK TIMER TIMER
ON/OFF
PROGRAM
RANDOM
REPEAT
AUTO
PRESET
DISPLAY
REVERSE MODE
MULTI CONTROL
REW FF
RM-RXVB55
REMOTE CONTROL
TAPE TUNER
BAND
FM MODE
C D
DOWN UP SET
AUX
VOLUME
AHB PRO
SOUND ACS
Supplement

RV-B550BU
1-2
Safety precautions
1.This design of this product contains special hardware and many circuits and components specially
for safety purposes. 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 performed 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 manufacturer`s
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 characteristics are often not evident from visual inspection nor can the protection afforded
by them necessarily be obtained by using replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these special safety characteristics are identified in
the Parts List of Service 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 characteristics 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 re-assembling.
5. Leakage current check (Electrical shock hazard testing)
After re-assembling the product, always perform an isolation check on the exposed metal parts
of the product (antenna 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 , particularly any exposed
metal part having a return path to the chassis, to a known good earth ground. Any leakage
current 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 1,000 ohms
per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by
a 0.15 F AC-type capacitor between an exposed
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.).
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.
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
!
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 preforming repair of this system.

RV-B550BU
1-3
Importance administering point on the safety
RV-B550J ONLY
Full Fuse Replacement Marking
Graphic symbol mark
(This symbol means fast blow type fuse.)
should be read as follows ;
FUSE CAUTION
FOR CONTINUED PROTECTION AGAINST RISK
OF FIRE, REPLACE ONLY WITH SAMETYPE
AND RATING OF FUSES ;
F1901 : 1.0-A, 250-V
F1902 : 6.3-A, 125-V
F1903 : 6.3-A, 125-V
F1904 : 6.3-A, 125-V
F1901 : 1.0-A, 250-V
F1902 : 6.3-A, 125-V
F1903 : 6.3-A, 125-V
F1904 : 6.3-A, 125-V
RV-B550J SEULEMENT
Marquage Pour Le Remplacement
Complet De Fusible
PRECAUTIONS SUR LES FUSIBLES
POUR UNE PROTECTION CONTINUE CONTRE
DES RISQUES D'INCENDIE, REMPLACER
SEULEMENT PAR UN FUSIBLE DU MEMETYPE ;
Le symbole graphique (Ce symbole signifie
fusible de type a fusion rapide.)
doit etre interprete comme suit ;
Note : It's means "J" for U.S.A. and Canada market model.

RV-B550BU
1-4
Important for laser products
1.CLASS 1 LASER PRODUCT
2.DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3.CAUTION : There are no serviceable parts inside the
Laser Unit. Do not disassemble the Laser Unit. Replace
the complete Laser Unit if it malfunctions.
4.CAUTION : The compact disc player uses invisible
laserradiation and is equipped with safety switches
whichprevent emission of radiation when the drawer is
open and the safety interlocks have failed or are de
feated. It is dangerous to defeat the safety switches.
5.CAUTION : If safety switches malfunction, the laser is able
to function.
6.CAUTION : Use of controls, adjustments or performance of
procedures other than those specified herein may result in
hazardous radiation exposure.
VARNING : Osynlig laserstrålning är denna del är öppnad
och spårren är urkopplad. Betrakta ej strålen.
VARO : Avattaessa ja suojalukitus ohitettaessa olet
alttiina näkymättömälle lasersäteilylle.Älä katso
säteeseen.
ADVARSEL : Usynlig laserstråling ved åbning , når
sikkerhedsafbrydere er ude af funktion. Undgå
udsættelse for stråling.
ADVARSEL : Usynlig laserstråling ved åpning,når
sikkerhetsbryteren er avslott. unngå utsettelse
for stråling.
REPRODUCTION AND POSITION OF LABELS
WARNING LABEL DANGER : Invisibie laser radiation
when open and interlock or
defeated.
AVOID DIRECT EXPOSURE TO
BEAM (e)
VARNING : Osynlig laserstrålning är
denna del är öppnad och spårren är
urkopplad. Betrakta ej strålen. (s)
VARO : Avattaessa ja suojalukitus
ohitettaessa olet alttiina
näkymättömälle lasersäteilylle.Älä
katso säteeseen. (d)
ADVARSEL :Usynlig laserstråling
ved åbning , når
sikkerhedsafbrydere er ude af
funktion. Undgå udsættelse for
stråling. (f)
CLASS 1
LASER PRODUCT
!
CAUTION
Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

RV-B550BU
1-5
Preventing static electricity
1. Grounding to prevent damage by static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged,
can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.
2. About the earth processing for the destruction prevention by static electricity
In the equipment which uses optical pick-up (laser diode), optical pick-up is destroyed by the static electricity of
the work environment.
Be careful to use proper grounding in the area where repairs are being performed.
2-1 Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over
it before placing the traverse unit (optical pickup) on it.
2-2 Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
3. Handling the optical pickup
1. In order to maintain quality during transport and before installation, both sides of the laser diode on the
replacement optical pickup are shorted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
2. Do not use a tester to check the condition of the laser diode in the optical pickup.The tester's internal power
source can easily destroy the laser diode.
4. Handling the traverse unit (optical pickup)
1. Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
2. Cut off the shorted part of the flexible cable using nippers, etc.after replacing the optical pickup. For specific
details, refer to the replacement procedure in the text. Remove the anti-static pin when replacing the traverse
unit. Be careful not to take too long a time when attaching it to the connector.
3. Handle the flexible cable carefully as it may break when subjected to strong force.
4. It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it
Conductive material
(conductive sheet) or iron plate
(caption)
Anti-static wrist strap
Attention when CD mecanism assembly is decomposed
1. Remove CD mechanism assembly.
2. Remove the four screws on the microcomputer board.
3. Disconnect the connector CN907 and CN602 on the microcomputer board.
4.The microcomputer board is put up as shown in Fig.1.
5. Solder is put up before the card wire is removed from connector CN601
on the maicroconputer board as shown in Fig. 2.
(When the wire is removed without putting up solder, the CD pick-up
assembly might destroy.)
6. Please remove solder after connecting the card wire with CN601 when
you install picking up in the substrate.
*Please refer to "Disassembly method" in the text for pick-up and how to
detach the CD mechanism.
Soldering
Fig.1
Fig.2
CD changer
mechanism
assembly
Microcomputer
board
Card wire
Flexible cable

RV-B550BU
1-6
Remove the six screws A attaching the side grille on
the left side of the body and pull out the side grille
from the body.
Similarly, remove the side grille on the right side.
1.
2.
When reassembling, make sure that
connector CN633 on the rear cabinet is
connected to the speaker terminal on the
front cabinet.
Attention:
Disassembly method
Removing the side grilles
(See Fig.1 and 2)
Prior to performing the following procedure, remove
the right and left side grilles.
Remove the battery cover on the back of the body.
Remove the eight screws Bon the back of the body
and detach the front cabinet assembly and the rear
cabinet assembly. Disconnect the connector CN904
on the LED (Illumination) board.
1.
2.
Removing the front cabinet assembly and
the rear cabinet assembly (See Fig.3
and 3a)
<Main Body>
Fig.1
Fig.2
Fig.3
Fig.3a
Side grille (left)
AA
Side grille (right)
AA
B
B
B
B
Push Push
Battery cover
CN904
LED (Illumination) board

RV-B550BU
1-7
The CD unit assembly cannot be removed if the
cassette mechanism assembly has not been
removed.
Prior to performing the following procedure, remove
the right and left side grilles, the front cabinet
assembly and the cassette mechanism assembly.
Remove the cassette chassis (See Fig.6).
Disconnect the card wires from connector CN631
and CN632 on the amplifier board.
Disconnect the card wires from connector CN403 on
the microcomputer board.
Remove the two screws Dattaching the CD
mechanism assembly on the back of the rear cabinet
(See Fig.8).
Pull out the CD unit assembly toward the front.
1.
2.
3.
4.
5.
Removing the CD unit assembly
(See Fig.6 to 8)
Prior to performing the following procedure, remove
the right and left side grilles and the front cabinet
assembly.
Disconnect the card wires from connector CN405
and CN406 on the microcomputer board located on
the underside of the CD unit of the rear cabinet
assembly.
Remove the four screws C attaching head shield and
the cassette mechanism assembly.
1.
2.
Removing the cassette mechanism
assembly (See Fig.4 and 5)
Fig.4
Fig.5
CN406 CN405
Microcomputer board
Cassette mechanism
assembly
Cassette chassis
Cassette mechanism assembly
C
C
CD unit assembly
CN403
Microcomputer board
CN632
CN631
amplifier board
Cassette chassis
Rear cabinet
D
CD unit assembly
Fig.6
Fig.8Fig.7
Head shield

RV-B550BU
1-8
Prior to performing the following procedure, remove
the right and left side grilles, the front cabinet assembly,
the cassette mechanism assembly and the cassette
chassis.
Disconnect the harness from connector CN192 and
CN193 on the power supply board respectively.
Remove the four screws F attaching the power
transformer assembly.
1.
2.
Remove the power transformer assembly
(See Fig.10)
Prior to performing the following procedure, remove
the right and left side grilles, the front cabinet
assembly, the cassette mechanism assembly, the
cassette chassis and the CD unit assembly.
Disconnect the 5pin harness from connector CN191
on the power supply board.
Remove the two screws Gand the one screw H
attaching the amplifier board.
Disconnect the harness from connector CN192 and
CN193 on the power supply board respectively.
Remove the two screws I attaching the power supply
board.
Pull out the battery board.
1.
2.
3.
4.
5.
Remove the amplifier board, the power
supply board and the battery board
(See Fig.11)
Prior to performing the following procedure, remove
the right and left side grilles, the front cabinet
assembly.
Disconnect the card wire from connector CN403 on
the microcomputer board.
Remove the screw Eattaching the tuner board
holder and pull out the tuner board holder together
with the tuner board. Disconnect the antenna wire
from TP1.
1.
2.
Removing the tuner board (See Fig.9)
Fig.11
Microcomputer board
CN403
TP1
Antenna wire
Tuner board
Tuner board holder E
F
F
CN193
CN191CN192
Power transformer assembly
Power supply board
G
H
I
CN631
CN631
Battery board
CN193
CN192
Power supply board
Amplifier board
CN191
Fig.10
Fig.9

RV-B550BU
1-9
Disconnect the card wire from connector CN251 and
CN252 on the key switch board on the front side of
the CD unit assembly.
Remove the four screws Jattaching the microcomputer
board on the underside of the CD unit assembly.
Disconnect the card wire or the harness from
connector CN601, CN602 and CN907 on the
microcomputer board respectively.
1.
2.
3.
Removing the microcomputer board
(See Fig.12 and 13)
Prior to performing the following procedure, remove
the microcomputer board.
Release the four tabs afixing the right and left
function buttons and the three tabs bby the key
switch board.
Push tabs aand bin the directions of the arrows
carefully not to damage the function buttons
Remove the six screws Kattaching the key switch
board.
Pull out the key switch board from two tabs c.
1.
2.
3.
Removing the key switch board
(See Fig.14 and 15)
<CD unit assembly>
Fig.15
Fig.14
Fig.12
PushPush
CN252 CN251
Microcomputer board
Microcomputer board
J
J
J
J
CN602
CN601 CN907
Push PushPushPush PushPushPush
Push
a
b
a
b
Key switch board
Function switch buttons
(power) Function switch buttons
(volume)
Key switch board c
c
KK
a
Key switch board
PushPushPush
Fig.13

RV-B550BU
1-10
Prior to performing the following procedure, remove
the microcomputer board.
Release the two tabs dfixing the CD door switch
board on the back of the CD unit assembly.
1.
Removing the CD door switch board
(See Fig.16)
Prior to performing the following procedure, remove
the microcomputer board.
Remove the four screws Lattaching the CD mechanism
holder on the back of the CD unit assembly.
Remove the CD mechanism holder, the CD cushion
and the CD mechanism assembly respectively.
1.
2.
Removing the CD mechanism assembly
(See Fig.16)
Prior to performing the following procedure, remove
the CD mechanism assembly.
Remove the four screws Mattaching the pickup cover.
Push the shaft stopper by the turn table in the direction
of the arrow and pull out the shaft.The pickup assembly
comes off.
1.
2.
Removing the pickup assembly
(See Fig.17 to 19)
M
M
M
Pickup cover
Pickup assembly
Turn table
Shaft stopper
Shaft Pickup assembly
Turn table
Shaft stopper
Shaft
Fig.16
L
L
CD door switch
board
d
CD mechanism
Assembly
CD cushion CD mechanism holder
Fig.17
Fig.19
Fig.18

RV-B550BU
1-11
Prior to performing the following procedure, remove
the front cabinet assembly and the rear cabinet
assembly.
Remove the eight screws Pattaching the right and
left speakers on the inside of the front cabinet assembly.
Remove the screw Q attaching the speaker terminal.
1.
2.
Removing the speakers (See Fig.20)
<Front Cabinet Assembly>
Prior to performing the following procedure, remove
the front cabinet assembly and the rear cabinet
assembly.
Remove the two screws Nand two screws O
attaching the LED boards on thespeaker.
Disconnect the harness from connector FW251 and
FW261.
1.
2.
Removing the LED boards (See Fig.20)
Fig.20
P
PP
Q
Speaker terminal
Speaker Speaker
LED board LED board
O
N
PFW261
FW251

RV-B550BU
1-12
<<Cassette mechanism section>>
Removing the playback/recording & eraser
head ( See Figs.1 and 2 )
1.While shifting the trigger arms seen on the right
side of the head mount in the arrow direction,
turn the flywheel R in counterclockwise direction
until the head mount has gone out with a click
(See Fig. 1).
2.When the flywheel R is rotated in counterclockwise
direction, the playback/recording & eraser head
will be turned in counterclockwise direction from the
position in Fig. 2 to that in Fig. 3.
3. At this position, disconnect the flexible P.C. board
(outgoing from the playback/recording & eraser head)
from the connector CN31 on the head amplifier &
mechanism control P.C.board.
4. After dismounting the FPC holder, remove the flexible
P.C. board.
5. Remove the flexible P.C. board from the chassis base.
6. Remove the spring afrom behind the playback/recording
& eraser head.
7. Loosen the reversing azimuth screw retaining the playback
/recording & eraser head.
8.Take out the playback/recording & eraser head from the
front of the head mount.
9.The playback/recoring & eraser head should also be
removed similarly according to Steps 1 ~ 8 above.
Reassembling the playback/recording
& eraser head
1. Reassemble the playback head from the front of the head
mount to the position as shown in Fig. 3.
2. Fix the reversing azimuth screw.
3. Set the spring afrom behind the Playback/Recording &
Eraser head.
4. Attach the flexible P.C. board to the chassis base, and fix
it with the FPC holder as shown in Fig. 3.
5.The playback/recording & eraser head should also be
reassembled similarly to Step 1 ~ 4 above.
Cassette mechanism
Flywheel R
Trigger armHead mount Fig. 1
Fig. 2
Playback/recording &
eraser head
Frexible
board
Spring a
Trigger arm
Head amplifier & mechanism
control P.C. board Flywheel R
Fig. 3
Playback/recording &
eraser head Reversing azimuth
screw
Head
mount
Frexible
board
Spring "a"
FPC holder Head amplifier &
mechanis control
P.C. board

RV-B550BU
1-13
Removing the head amplifier & mechanism
control P.C. board (See Fig. 4)
1. Remove the cassette mechanism assembly.
2. After turning over th cassette mechanism assembly,
remove the three screws Aretaining the head
amplifier & mechanism control P.C.board.
3. Disconnect the connector CN32 on the P.C. board
including the connector CN 1 on the reel pulse P.C.
board.
4.When necessary, remove the 4 pin parallel wire
soldered to the main motor.
Removing the main motor assembly
1. Remove the two screws Bretaining the main
motor assembly (See Fig. 4, 4a).
2.While raising the main motor, remove the capstan
belt from the motor pulley (See Fig. 4a).
Caution 1: Be sure to handle the capstan belt so
carefully that this belt will not be
stained by grease and other foreign
matter. Moreover, this belt should be
hanged while referring to the capstan
belt hanging method in Fig. 5, 6.
Fig. 4a
Main motor
assembly
Capstan belt
Motor
pulley
Fig. 6
Main motor
assembly
Flywheel
Motor pulleyCapstan belt
Fig. 5
Mechanism motor
assembly
Motor
pulley
Capstan
belt
(See Fig. 4~6)
Belt
Main motor
assembly
Head amplifier &
mechanism control
P.C. board
Flexible P.C. board
4pin parallel wire
Main
moteor
assembly
Fig. 4
AA
A
B
B

RV-B550BU
1-14
Removing the flywheel
(See Figs.7 and 8)
1. Remove the head amplifier & mechanism control
P.C. board.
2. Remove the main motor assembly.
3. After turning over the cassette mechanism,
remove the slit washers band cfixing the capstan
shafts R and L, and pull out the flywheel R and L
respectively from behind the cassette mechanism.
Removing the reel pulse P.C. board and solenoid
(See Fig. 9)
1. Remove the five pawls d~hand screw Creataining the reel pulse
P.C. board.
2. From the surface of the reel pulse P.C. board parts, remove
the two pawls iand jretaining the solenoid.
Flywheel R Flywheel L
Capstan shaft R Capstan shaft L
Slit
washer Slit washer
Fig. 8
i
hd ef
C
g
Flywheel R Flywheel L
Fig. 9
Reel pulse P.C. board
Solenoid
Fig.7
Cb
j

RV-B550BU
1-15
Adjustment method
Measuring devices necessary for adjustment
1. Low-frequency oscillator
It must have the ability to output 600ohm from 0 dBs
at an oscillation frequency of 20 Hz 50 Hz.
2.Attenuator impedance: 600ohm
3.Electronic voltmeter
4.Distortion meter
5.Frequency counter
6.Wow and flutter meter
7.Test tapes
VT-712: tape speed and rotational distortion (3 kHz)
VT-724: standard level (1 kHz)
VT-703: head angle adjustment (10 kHz),
or use VT-73
VT-739: reproduction of frequency characteristics
(1 kHz, 63 Hz, 10 kHz)
8.Blank tape
Type I : AC-225 (TDK-AD)
Type II : AC-514 (TDK-SA)
9.Torque gauge: Tension gauge for playback,
fast-forward and rewind.
FWD (TW211A), REW (TW212A)
and FF/REW (TW2231A)
Specifications for measurement
Power supply voltage ................... AC 100 V (50/60 Hz)
Standard output ........................ Speaker: 0.775V/4ohm
Headphone:0.245V/32ohm
Standard frequency and input level
................... 1 kHz: AUX: -8 dBs
Input level for reproduction of recording characteristics
................... AUX: -28 dBs
Measuring output terminal ................... Speaker: CN633
Load resistance .................................................... 4ohm
Radio input signal
AM frequency ..................................................... 400 Hz
Degree of modulation in AM band .......................... 30%
FM frequency ...................................................... 400 Hz
Frequency deviation in FM band ..................... 22.5 kHz
Tuner section
Voltage input to the tuner .......................... +B: DC 5.7 V
VT: DC 12 V
Standard measuring output ...... 26.1 mV (0.28 V) /3ohm
Input locations ..................... AM: standard loop antenna
FM: TP1 (hot) and TP2 (GND)
Standard settings for measuring volume
Sound ..................................................................... OFF
Effective hyper bass ............................................... OFF
Volume adjustment ........................................... VOL. 23
Precautions for measuring
1.Input 30 pF and 33 kohm to the IF sweeper output
and 0.082 F and 100 kohm to the sweeper input,
respectively.
2.Lower the output level of the IF sweeper as much as
possible in the adjustable range.
3.The IF sweeper needs no adjustment as it is a fixed
component.
4.It is not necessary to perform any kind of adjustment
on the MPX, as a ceramic oscillator is used for
measuring.
5.FM tracking adjustment is not necessary as a fixed
coil is used.
6.The grounding circuit is separate from the input and
output. Therefore, be sure to connect to ground
carefully when measuring both the input and output
voltages simultaneously using 2 channels of the
electronic voltmeter.
7.The speaker's minus terminal cannot be connected to
ground when using a BTL format amplifier. Therefore,
do not connect any type of ground wire to this
terminal. The OTL format is used with this system.
8.Use a large wire to connect to the dummy impedance
generator when measuring the output.
9.Be sure to use a band pass filter (DV-12) when using
mixed tape.

RV-B550BU
1-16
CN31
Location of parts to be adjusted
Cassette handling mechanism Cassette handling mechanism (reverse side)
Location of parts to be adjusted
Head for recording, playing
and erasing the tape
Head azimuth
adjusting screw (fast-forward)
Head azimuth adjusting
screw (rewind)
Head azimuth adjusting
screw (fast-forward) Head azimuth adjusting
screw (rewind)
Head for recording,
playing and erasing the tape
VR37
Motor speed
TP
Bias oscillation frequency (wide pattern)
L301
Bias oscillation frequency
VR31
Lch recording frequency (bias adjustment)
VR32
Rch recording frequency (bias adjustment)

RV-B550BU
1-17
Adjustment of cassette handling mechanism
Items Condition Method for adjustment
and confirmation Standard value Parts to be adjusted
Confirmation
of head angle Test tape: VT-703 (10 kHz) Measuring output terminal:
Speaker terminal, speaker (R)
(Load resistance: 4 ),
headphone terminal
(1) Play back the VT-703 test tape.
(2) Adjust the head azimuth screws so
that the tape playback mechanism
records the maximum output level in
both the fast-forward and rewind
direction.
(3) In all cases, both the fast-forward and
rewind direction should be adjusted
using head azimuth screws.
Maximum
output Adjust the head
azimuth
screws
when
changing
the head.
Confirmation
of tape speed Test tape: VT-712 (3 kHz) Measuring output terminal:
Headphone terminal
Adjust VR37 so that the frequency
counter records 3,015 Hz 15 Hz when
playing back the end of the VT-712 test
tape (3 kHz) in the fast-forward direction.
Tape speed
of cassette
deck: 3,015
Hz 15 Hz
VR37
Items to be confirmed and standard values
Items Condition Method for adjustment
and confirmation Standard value Parts to be adjusted
Difference in
speed
between fast-
forward and
rewind
Test tape: VT-712 (3 kHz)
Measuring output terminal:
Speaker terminal, speaker (R)
(Load resistance: 4 ),
headphone terminal
The difference between fast-forward and
rewind should be less than 60 Hz on the
frequency counter when playing back the
beginning of the VT-712 test tape (3 kHz)
in both directions.
Less than 60
Hz Should be confirmed
when
changing
the motor.
Wow and
flutter Test tape: VT-712 (3 kHz) Measuring output terminal:
Headphone terminal
Wow and flutter should be recorded at
less than 0.25% (WRMS) when playing
back the VT-712 test tape (3 kHz) in the
fast-forward direction.
Less than
0.25%
(WRMS)
Electronic performance
Items Condition Method for adjustment
and confirmation Standard value Parts to be adjusted
Confirmation
of output Measuring output terminal: CN34-5 or 7-terminal
preamp base
Test tape: VT-724
Confirm that the output from the CN34-5
or 7-terminal preamp base connector is -
25 dBs 3 dB when playing back the VT-
724 test tape.
Reference value: The output from the
headphone terminal is -7 dB 4 dB.
Output of CN34-
5 terminal: -25
dBs 3 dB
Difference
between Lch
and Rch: within
3 dB
Confirmation
of
reproduction
of frequency
characteristics
Measuring output terminal:
Headphone terminal
Test tape: VT-739
Confirm that the 10 kHz reproduction
level is -1 dB 5 dB compared to the 1
kHz reproduction level when playing back
the VT-739 test tape.
Difference
between 10
kHz and 1 kHz
should be -1
dB 5 dB.
Recording
bias
frequency
Fast-forward or rewind
direction:
Test tape: TYPE II (AC-
514)
Measuring terminal: Bias
TP on the base
Switch the bias (beat cut switch) between
1 and 2 to confirm that the frequency
changes. Load the test tape (AC-514 for
TYPE II) into the mechanism and preset
it to the record-pause mode.
Confirm that the bias TP frequency on
the base is 100 kHz 6 kHz.
100 kHz 6 kHz

RV-B550BU
1-18
Standard values for confirmation of electronic performance
Items Condition Method for adjustment
and confirmation Standard value Parts to be adjusted
Erasing
current
(standard
and
reference
value)
Fast-forward and
rewind direction:
Recording mode
AC-514 for TYPE II,
AC-225 for TYPE I
Measuring terminal:
Both erase head ter
minals
Load the test tape (AC-514 for TYPE II,
AC-225 for TYPE I) into the tape
playback mechanism and preset it to the
record-pause mode.
After setting it to the recording mode,
send 1 M in series to the erase head and
measure the erasing current from both
erase head terminals.
TYPE II: 110
mA
TYPE I: 75 mA
Adjustment of
reproduction
of frequency
characteristics
Standard frequencies:
1 kHz and 10 kHz
(REF: -20 dB)
Test tape: TYPE II:
AC-514
Measuring input
terminal: OSC IN
Load the test tape (AC-514 for TYPE II,
AC-225 for TYPE I) into the tape
playback mechanism and preset it to the
record-pause mode.
Input the standard value of -20 dB and
the standard frequencies of 1 kHz and 10
kHz repeatedly to the microphone input
from the transmitter in the recording
mode. Adjust VR31 for Lch and VR32 for
Rch so that the difference in level
between 10 kHz and 1 kHz is -1 dB 5
dB.
Repeat the above for TYPE I and confirm
that the difference in level is -XdB dB.
Difference in
output
between 1 kHz
and 10 kHz: -1
dB 5 dB
Lch: VR31
Rch: VR32
Sensitivity of
reproduction
of
microphone
mixing
Microphone input
terminal: 1 kHz, -65 dB
Test tape: VT-724
Based on the reproduction level of the
VT-724 test tape, confirm that the
microphone level is 0 dBs 3 dB when a
1 kHz, 65 dBs signal is input.
(The mixing volume and sound volume
should be at maximum.)
0 dBs 3 dB
(Based on the
reproduction
level of the
VT-724)
(U version only)

RV-B550BU
1-19
Flow of functional operation until TOC read
Slider turns REST
SW ON.
Automatic tuning
of TE offset
Laser ON
Detection of disc
Automatic measurement of
Focus A-curve amplitude
Automatic tuning of
Foucus offset
Disc is rotated
Focus servo ON
(Tracking servo ON)
Automatic tuning of
Tracking error balance
Automatic measurement of
Tracking error amplitude
Automatic tuning of
Focus error balance
Disc to be
braked to stop
Tracking
servo
on statas
Tracking
servo
off statas
Disc statas
to rotate TOC reading
finishes
Automatic measurement
of TE amplitude and
automatic tuning of
TE balance 500mv/div
2ms/div Fig.1
Approx.3sec
pin 25 of
IC601(TE)
Approx
1.8V
VREF
Tracking error waveform at TOC reading
Power ON Power Key
Confirm that the Focus error
S-cuve siganl at the pin27 of
IC601 is approx.2Vp-p
Confirm that the siganl from
pin24 IC603 is 0V as a
accelerated pulse during
approx.400ms.
Confirm the waveform of
the Tracking error signal
at the pin25 of IC601 (R612)
(See fig-1)
Automatic tuning of
Focus error gain
Automatic tuning of
Tracking error gain
TOC reading
Play a disc
Confirm the eys-pattern
at the lead of TP602
Check that the voltage at the pin 5
of CN602 (or pin 5 of IC901)
is 0V (a moment)?
Check Point
Check that the voltage at the
pin3 of IC601 + side is + 5V?

RV-B550BU
1-20
Turn off the power switch and,disconnect the
power cord from the ac outlet.
Replace the pickup with a normal one.(Refer
to " Pickup Removal " on the previous page)
Plug the power cord in,and turn the power on.
At this time,check that the laser emits for
about 3seconds and the objective lens moves
up and down.
Note: Do not observe the laser beam directly.
Play a disc.
Check the eye-pattern at TP1.
Finish.
Maintenance of laser pickup
(1) Cleaning the pick up lens
Befor you replace the pick up, please try to
clean the lens with a alcohol soaked cotton
swab.
(2) Life of the laser diode (Fig.1)
When the life of the laser diode has expired,
the following symptoms wil appear.
(1) The level of RF output (EFM output:ampli
tude of eye pattern) will below.
Is RF output
1.1 0.15Vp-p? Replace it.
NO
YES
O.K
(3) Semi-fixed resistor on the APC PC board
The semi-fixed resistor on the APC printed
circuit board which is attached to the pickup
is used to adjust the laser power.Since this
adjustment should be performed to match the
characteristics of the whole optical block,
do not touch the semi-fixed resistor.
If the laser power is lower than the specified
value,the laser diode is almost worn out, and
the laser pickup should be replaced.
If the semi-fixed resistor is adjusted while
the pickup is functioning normally,the laser
pickup may be damaged due to excessive current.
(Fig.1)
Replacement of laser pickup