JVC RC-BX33SL User manual

SERVICE MANUAL
PORTABLE CD SYSTEM
Contents
Safety precautions ............................................................ 1-2
Preventing static electricity ...............................................1-3
Disassembly method .........................................................1-4
Adjustment method............................................................ 1-7
Description of major IC ..................................................1-13
RC-BX33SL
IMPORTANT
PLEASE TAKE NOTE BEFORE ORDERING
1. Order all service parts thro gh JVC Asia Pte Ltd.- C stomer Satisfaction Dept.
2. Two orders are available: Initial order and last order (Before End Of Line)
3. Minim m order q antity: 100pcs
4. Delivery term: Minim m 2 months pon confirmation of order.
No: 28208
DEC. 2001
COPYRIGHT 

2001 JVC ASIA PTE LTD
RC-BX33SL
Area Suffix
UX---Saudi and relative
U---Except ux

XL-SV320SL/SV305GD
XL-SV308BU
1-2
RC-BX33SL
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
authorised 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, 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, tubing’s, 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 and 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
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.
0.15µF 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.).
Safety precautions
0.15µF AC TYPE
1500 10W
Place this
probe on
each exposed
metal part.
Good earth ground
AC Voltmeter
(Having 1000
ohms/volts,
or more sensitivity
! CAUTION Burrs formed during moulding may be left over on some parts of the chassis. Therefore,
pay attention to such burrs in the case of performing repair of this system.

RC-BX33SL
1-3
Preventing static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is dis-
charged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when
performing repairs.
1.1. Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players.
Be careful to use proper grounding in the area where repairs are being performed.
1.1.1. Ground the workbench
1. 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.
1.1.2. Ground yourself
1. Use an anti-static wrist strap to release any static electricity built up in your body.
1.1.3. 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.
1.2. 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 spe-
cific 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

RC-BX33SL
Disassembly method
Removing the rear panel
1.
From behind the body, remove the Five screws
A
retaining the rear panel.
2.
Open the Battery door, then remove One Screw
B
retaining in the battery compartment
bottom side.
3
Then remove the Two screws
C
retaining the bottom of rear panel.
4
Take out the rear panel from the body. And disconnect the CN302 on the main board
right side.
Note:
Be careful of the FM antenna white wire, it is connection with the tuner PCB up side.
You can directly take out from the tuner PCB.
When you re-assembly the product, plug the FM antenna white wire into the Tuner
PCB'S "FM ANT" position.
Screw A.
Screw A.
Screw C.
Screw C.
Screw B.
1-4

RC-BX33SL
Removing the Main Board PCB (1)
1.
Open & remove the rear panel
2.
Remove the Two Screws
D
on the Black Backet,
then take out the black backet on the
front panel.
Screws D.
3
Remove the Two Screws
E
retaining on the
left of front panel.
Screws E.
4
Remove the One Screw
F
retaining on the
right of front panel.
Top panel
Screw F.
1-5

RC-BX33SL
Removing the Main Board PCB (2)
5
Disconnect the CN201, CN202 & C301 on the top of the
Main Board PCB.
Front Panel
CN 201
CN 202
Main PCB
CN 301
Top Panel
6
Then, take out the top panel from the front panel.
7
Remove the nine screws
G
from the Main Board PCB.
Screw G.
Screw G.
Screw G.
8
Take out the Main Board PCB from the front panel, & disconnect the CN901 & CN903
on the Main Board PCB.
1-6

RC-BX33SL
Adjustment method
Measurement instruments required for
Tuner section
adjustment
1Low frequency oscillator Reference measurement ----- 26.1mV(0.63/8)
This oscillator should have a capacity to output output
0dB to 600 at an oscillation frequency of Input positions ----- AM : Standard loop antenna
50Hz-20KHz FM : TP1 (hot) and TP2 (GND)
2Electronic voltmeter
3Distortion meter Precautions for measurement
4Frequency counter 1Direct connect to the IF sweeper output
5Wow & flutter meter side and 1UF and 22 Kohm connect to the
6Test tape sweeper input side. Same as FIG1.
TCC-112: Tape speed and running unevenness (3KHz) 1 U
TCC-140: Reference level (1KHz) IC101 TP16
TCC-182A: Head angle (8KHz), playback frequency PIN18 22 K
characteristics (1KHz) and dubbing
frequency TP8
characteristics (125Hz and 8KHz)
7Blank tape 2The IF sweeper output level should be made as
TYPE I : TDK-D60 low as possible within the adjustable range.
3Since the IF sweeper is a fixed device, there is
8Torque gauge : For play and back tension no to adjust this sweeper.
FWD(CT-120m), and FF/REW(CT-F) 4Since a ceramic oscillator is used, there is no
need to perform any MIX adjustment.
Measurement conditions 5Since a fixed coil is used, there is no need to
adjustment the FM tracking.
Power supply voltage -------------- AC120V (60Hz) 6
The input and output earth systems are separated.
Reference output -------------- Speaker : 0.63V/8 In case of simultaneously measuring the voltage
Headphone : 0.245V/32 in both of the input and output systmes with and
electronic voltmeter for two channels, therefore,
the earth should be connected particularly
Input for confirming recording and ------- CD : -10dB carefully.
playback characteristics 7For connecting a dummy resistor when measuring
Measurement output terminal ------- Speaker CN301 the output, use the wire with a greater code size.
* Load resistance -------------------------------------- 8 8Whenever any mixed tape is used, use the band
pass filter (DV-12V).
Radio Input signal
AM frequency -------------------------------- 400Hz
AM modulation ---------------------------------- 30%
FM frequency --------------------------------- 1 KHz
FM frequency deviation ------------------ 22.5KHz
1-7

RC-BX33SL
TAPE DECK ADJUSTMENTS
1
HEAD AZIMUTH ADJUSTMET
( 1 ) Load the test tape TCC-182A 8KHz for azimuth
adjustment.
( 2 ) Press the PLAY button.
Use a cross-tip screwdriver to turn the screw for azimuth
( 3 ) adjustment so that the left and right output are maximized
( 4 ) Press the STOP button
( 5 ) After completion of the adjustment. Use thread lock(TB-1401B)
to secure the azimuth-adjustment screw.
2
AC BIAS FREQUENCY ADJUSTMENTS
( 1 ) Connect frequency counter to CN201(BS);
( 2 ) R/P swith in recording state;
( 3 ) Adjusting T201 use a plastic screwdriver, AC bias frepuency;62+-1KHZ..
3
TAPE SPEED ADJUSTMENT
( 1 )
Insert the test tape(MTT-111N,3,000 HZ)
( 2 ) Press the PLAY button.
( 3 ) Use a flat-tip screwdriver to turn the MOTOR VR
adjust MOTOR VR so that the frequency counter
become 3,000Hz
CASSETTE MECHANISM SECTION
CASS DECK
P/R HEAD
HEAD AZIMUTH ADJUSTING SCREW
1-8

RC-BX33SL
Tape recorder section
Items Measurement Measurement method Standard Adjusting
conditions Values positions
Confirmation Test tape 1 Playback the test tape TCC-182A (8KHz) Maximum Adjust the head
of head angle :TCC-182A(8KHz) 2 With the recording & playback mechanism, output azimuth screw
Measurement output adjust the head azimuth screw so that the only
terminal left and right output levers become
:Speaker terminal maximum, After adjustment, lock the
Sparker R head azimuth at least by half turn.
(Load resistance:8)
:Headphone terminal
Confirmation Test tape Adjust VR401 so that the frequency counter Tape speed MOTOR VR
of tape speed :TCC-112(3KHz) reading becomes 3,010Hz +/-15Hz when of deck
Measurement output playing back the test tape TCC-112 (3KHz) :3,010Hz
terminal with playback and recording mechanism +/-15Hz
:Headphone terminal after ending forward winding of the tape.
Reference Values for Confirmation Items
ITEMS Measurement Measurement method Standard Adjusting]
conditions Values positions
Wow & flutter Test tape When the test tape TCC-112 (3KHz) has been 0.25% or
:TCC-112(3KHz) played back with the recording and playback less
mechanism at the beginning of forward (WRMS)
Measurement output winding, the frequency counter reading of
terminal wow & flutter should be 0.25% or less
:Headphone terminal (WRMS).
1-9

RC-BX33SL
Electrical Performance
ITEMS Measurement Measurement method Standard Adjusting
conditions Values positions
Adjustment of * Mode: PB mode 1 With the recording and playback mechanism,
recording bias * Recording mode load the test tapes TDK-D60, and set the TDK-D60
current * Test tape: TDK-D60 mechanism to the recording and pausing 4.5A
(Reference condition in advance . +/-0.5A
Value) * Measurement output
terminal 2 After connecting 100ohms in series to the
:Both recording and recorder head, measure the bias current
headphone terminals with a valve voltmeter at both of the
terminals
Adjustment of * Reference frequency 1 with the recording and playback mechanism, Output
recording and :1KHz and 8KHz load the test tapes (TDK-D60) and set the deviation
playback (REF.:- 10dB) mechanism to the recording and pausing between
frequency * Test tape: TDK-D60 condition in advance. 1KHz and
characteristics 8KHz
* Measurement input 2 While repetitively inputting the reference :-1dB +/-2dB
terminal: OSC IN frequency signal of 1KHz and 8KHz from
OSC IN, record and playback the tape.
3 While receding and playback the test tape
Lch and Rch so that the output
deviation between 1KHz and 8KHz becomes
-1dB +/-2dB
Reference Values for Electrical Function Confirmation Items
Items Measurement Measurement method Standard Adjusting]
conditions Values positions
Recording * Playback 1 While changing over to and form BIAS 1 62KHz T201
bias * Test tape: TDK-D60 and 2, confirm that the frequency is +/-6KHz
frequency changed
* Measurement
2 With the recording and playback
terminal : BIAS TP on mechanism, load the test tape.
P.C. board (TDK-D60 ) , and set the
mechanism to the recording and pausing
condition in advance.
3 Confirm that the BIAS TP frequency on the
P.C. board is 62KHz +/-6KHz
1-10

RC-BX33SL
Flow of functional operation until TOC read Check Point
Check that the voltage at the pin
17 of CN901 is OV (a moment)?
Check that the voltage at the
pin1 of IC902 + side is + 5V?
Confirm that the Focus error
s-cuve signal at the pin16 of
IC902 is approx.2V p-p
Confirm that the signal from
TE waveform at TOC reading pin14 IC902 is 0V as a
accelerated pulse during
approx.400ms
Confirm the waveform of
the Tracking error signal
at the pin14 of IC902 (R926)
(See fig-1)
Confirm the eys-pattern
at the lead of TP1
Power Key Slider turns
REST SW ON.
Automatic tuning
of TE offset
Laser ON
Detection of disc
Auto tuning of
Focus offset
Auto. measurement of
focus A-curve amplitude
Disc is rotated
Focus servo ON
(Tracking servo ON)
Auto. measurement of
Tracking error amplitude
Automatic tuning of
Tracking error
Automatic tuning of
Focus error balance
Automatic tuning of
Focus error gain
Automatic tuning of
Tracking error gain
TOC reading
Play a disc
Approx 3sec
pin 25 of
IC601(TE)
Approx
1.8V
Trackin
g
servo
Tracking
servo on
statues
Disc to be
braked to
stop
TOC reading
finishes
Disc status
to rotate
Auto
measurement
of TE amplitude
and auto tuning
of TE balance 500mV/div
2mS/div Fig.1
VREF
1-11

TUNER ADJUSTMENTS
use aplastic screw driver for adjustments.
Adjust the intermediate frequency of AM and FM to the frequency of ceramic filter.
Supply voltage :DC 12.0 V
Speaker impedance :8OHMS
Function switch :RADIO
a. AM Adjustment BAND SELECT SWITCH : AM
ste Adjusting Tuning Input Connection Output Connection Adjustment Oscilloscope
circuit Frequency Measurement input Measurement output parts
1 IF 1000 KHz AM Sweep Loop TP4(H) T105
(455 / 465KHz) Generior ANT Oscilloscope TP8(E) (Non-adjustment)
2 Tuning 520KHz TP4(H) T102
3 Coverage 1640/1740 KHz -- -- Oscilloscope TP8(E) PVC4
4 600 KHz AM Signal Loop TP4(H) MW COIL
5 1400 KHz Generior ANT Oscilloscope TP8(E) PVC3 Maximum
b. FM Adjustment BAND SELECT SWITCH : FM FM Dummy Antenna : 75 ohm unbalance
ste Adjusting Tuning Input Connection Output Connection Adjustment Oscilloscope
circuit Frequency Measurement input Measurement output parts
1 IF FM Sweep TP4(H) TP4(H) T104
(10.7 MHz) 98.0 MHz Generator TP3(E) Oscilloscope TP8(E) T106
(Non-adjustment)
2 Tuning 87.4 MHz TP4(H) L104
3 Coverage 108.3 MHz -- FM ANT. Oscilloscope TP8(E) PVC2
4 90.0 MHz FM Signal FM ANT TP4(H) L103 Confirm with being
5 Tracking 106.0 MHz Generator TP1 (E) Oscilloscope TP8(E) PVC1 near by effective
TP2(H) sensitivity
1-12
RC-BX33SL

LA1824
1 2 3 4 5 6 7 8 9 10 11 12
24 23 22 21 18 16 15 14 13
AM
RF
AM
MIX
AM
OSC
FM
MIX
ST
LED
TUN
LED
FM
IF AM-IF
S-METER DET
PHASE
COMP
VCC2GND2
REG VCC1GND1
AGC
TRIG ST SW VCO FF FFFF
PILOT
DET
FM
RF
20
FM
OSC
19 17
DECODER DET
Pin No.
1
2
3
4
5
6
7
8
Pin No.
1
2
3
4
5
6
7
8
Function
AM-RF input
Reg
AM-OSC
VCC1
FM-MIX output
GND1
AM-MIX output
Tuning in dicator
Function
AM-RF input
Reg
AM-OSC
VCC1
FM-MIX output
GND1
AM-MIX output
Tuning in dicator
Pin No.
9
10
11
12
13
14
15
16
Pin No.
9
10
11
12
13
14
15
16
Function
AM-IF output
FM-IF input
AM-IF input
AM-AGC
FM-DET
Pilot detector filter
AM/FM Switch
L output
Function
AM-IF output
FM-IF input
AM-IF input
AM-AGC
FM-DET
Pilot detector filter
AM/FM Switch
L output
Pin No.
17
18
19
20
21
22
23
24
Pin No.
17
18
19
20
21
22
23
24
Function
R output
MPX input
AM/FM detector output
FM-OSC
VCC2
FM-RF output
GND2
FM-RF input
Function
R output
MPX input
AM/FM detector output
FM-OSC
VCC2
FM-RF output
GND2
FM-RF input
Major ICs Description
LA4227
1
2
3
4
5
6
1
2
3
4
5
6
STANDBY
OUT2
BS2
NF2
IN2
DC(FILTER)
STANDBY
OUT2
BS2
NF2
IN2
DC(FILTER)
7
8
9
10
11
12
7
8
9
10
11
12
PRE GND
IN1
NF1
BS1
OUT1
VCC
PRE GND
IN1
NF1
BS1
OUT1
VCC
BIAS
CIRCUIT
-
+
Ch1
THERMAL
SHUT DOWN
PROTECTION
STANDBY
SW
-
+
Ch2
Rf2
20KOHM RNF2 62KOHM
Rf1
20KOHM RNF1 62KOHM
12 10
11 9 7
8
13
24 6
5
STANDBY OUT2 BS2 PWR GND (TAB) NF2
IN2 DC(FILTER)
VCC OUT1 BS1 PWR GND (TAB) NF1 IN1 PRE GND
RC-BX33SL
1-13

1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
PW GND
OUT(-)1
PVCC1
OUT(+)1
VIN1
Vr1
Vc1
VIN2
PW GND
OUT(-)1
PVCC1
OUT(+)1
VIN1
Vr1
Vc1
VIN2
9
10
11
12
13
14
15
16
9
10
11
12
13
14
15
16
OUT(+)2
PVCC2
OUT(-)2
PW GND
PW GND
OUT(-)3
PVCC3
OUT(-)3
OUT(+)2
PVCC2
OUT(-)2
PW GND
PW GND
OUT(-)3
PVCC3
OUT(-)3
17
18
19
20
21
22
23
24
17
18
19
20
21
22
23
24
VIN3
SGND
SVCC1
VIN4
OUT(+)4
PVCC4
OUT(-)4
PW GND
VIN3
SGND
SVCC1
VIN4
OUT(+)4
PVCC4
OUT(-)4
PW GND
TA2092N
1-14
RC-BX33SL

TA2153FN
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
- +
-
+
-
+
-
+
BOTTOM
PEAK
AGC Amp.
- +
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
-
+
-
+
-
+
-
+
-
+
3 STATE
DET
I-I
-
+
-
+
I-I
-
+
-
+
-
+
-
+
-
+
10pF
20K
60K
20K
20K
12K
12K
20K
11K
100
100K
100K
11K
20K
36pF
10K 50K
15K
15K 3pF
30K
10K
10K
30K 3pF 10pF
20K
48K
21.82K
2.9K 83K SW1
1K
SW2
SW3 1.4K
2.26K
13K
238K
15pF
238K
15pF
90K
60K 60K
20K 150K
40pF
1K
1K
150K
40pF
Pin No.
1
2
3
4
5
6
Pin No.
1
2
3
4
5
6
Function
VCC
RFGC
GMAD
FNI
FPI
TPI
Function
VCC
RFGC
GMAD
FNI
FPI
TPI
Pin No.
13
14
15
16
17
18
Pin No.
13
14
15
16
17
18
Function
TEN
TEO
SBAD
FEO
FEN
SEB
Function
TEN
TEO
SBAD
FEO
FEN
SEB
Function
TNI
MDI
LDO
SEL
TEB
2VRO
Function
TNI
MDI
LDO
SEL
TEB
2VRO
Pin No.
7
8
9
10
11
12
Pin No.
7
8
9
10
11
12
Function
VRO
RFRP
BTC
RFCT
PKC
RFRPIN
Function
VRO
RFRP
BTC
RFCT
PKC
RFRPIN
Pin No.
19
20
21
22
23
24
Pin No.
19
20
21
22
23
24
Pin No.
25
26
27
28
29
30
Pin No.
25
26
27
28
29
30
Function
RFGO
GVSW
AGCIN
RFO
GND
RFN2
Function
RFGO
GVSW
AGCIN
RFO
GND
RFN2
RC-BX33SL
1-15

JVC Asia Pte Ltd
101 Thomson Road, #28-04 United Squares, Singapore 307591
(No: 28208) Printed in Singapore
200104(L)
RC-BX33SL

SERVICE MANUAL
PORTABLE CD SYSTEM
Contents
Block diagram ...................................................................2-2
Wiring diagram .................................................................2-3
Schematic diagram ........................................................... 2-4
Printed circuit boards .......................................................2-6
RC-BX33SL
IMPORTANT
PLEASE TAKE NOTE BEFORE ORDERING
1. Order all service parts thro gh JVC Asia Pte Ltd.- C stomer Satisfaction Dept.
2. Two orders are available: Initial order and last order (Before End Of Line)
3. Minim m order q antity: 100pcs
4. Delivery term: Minim m 2 months pon confirmation of order.
No: 28208sch
DEC. 2001
COPYRIGHT 

2001 JVC ASIA PTE LTD
RC-BX33SL
Area Suffix
UX---Saudi and relative
U---Except UX

2-2
RC-BX33SL
BLOCK DIAGRAM
CD SW
CD SW
R/P SW
R R/P
L R/P
IC 201 TA2068
R/P PRE.AMP
SIGAL R/P SLECT. SW
AM ANT
AM OSC
TU-5V
REG.
IC903
TA2092N
MOTER DRIVER
IC301 LA4227
POWER AMP
L. SPEAKER
R. SPEAKER
OPTICAL PICKUP
IC902
TA2153FN
HEAD AMP
LCD KE
CD DOOR
LEAF - SW
IC902
TA9457F
(DSP/MCU)
REM
DISC
FM RF FM OSC
FM F/E, IF/DET/MPX
AM RF/IF/DET
(IC101 LA1824)
BPF
FM ANT
Q401
8V REG
DC SUP
SW
CASS. DECK
LEAF - SW
R/P HEAD
ERASE HEAD

RCRC-BX33SL
2-3
Wiring Diagram

Circuit Diagram -1 RC-BX33SL
2-4