JVC AV-27530/SC User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.YA050B
2005/11
COLOR TELEVISION
YA050B200511 AV-27530/SC
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
BASIC CHASSIS
FE5

1-2 (No.YA050B)
SPECIFICATION
Design & specifications are subject to change without notice.
Items Contents
Dimensions (W ×H ×D) 65.4 cm ×59.3 cm ×49.4 cm (25-3/4" ×23-3/8" ×19-1/2")
Mass 31.1 kg (68.5 Ibs)
TV RF System CCIR (M)
Color System NTSC
Sound System BTSC (Multi Channel Sound)
Teletext System Closed Caption (T1 - T4 / CC1 - CC4)
TV Receiving Channels
and Frequency VHF low VHF high
UHF
CATV
02ch - 06ch: 54 MHz - 88 MHz
07ch - 13ch: 174 MHz - 216 MHz
14ch - 69ch: 470 MHz - 806 MHz
54MHz - 804 MHz
Low Band: 02 - 06
High Band: 07 - 13
Mid Band: 14 - 22
Super Band: 23 - 36
Hyper Band: 37 - 64
Ultra Band: 65 - 94, 100 - 135
Sub Mid Band: 01, 96 - 99
TV / CATV Total Channel 181 Channels
[Reception of channel A-5 ("95" of the TV set’s on-screen CABLE channel) is
recommended for your TV set.]
Intermediate Frequency Video IF
Sound IF 45.75 MHz 41.25 MHz (4.5 MHz)
Color Sub Carrier 3.58 MHz
Power Input AC120 V, 60 Hz
Power Consumption 105 W
Picture Tube (Visible size) 68 cm (27") Measured diagonally (H: 55.4 cm ×V: 41.8 cm)
High Voltage 30.0 kV ±1.3 kV [at Zero beam current]
Speaker 5 cm ×9 cm (2" ×3-1/2"), Oval type ×2
Audio Power Output 1.2 W + 1.2 W
Antenna Terminal (VHF / UHF) F-type connector, 75 Ωunbalanced
Video / Audio input
[Input-1/2/3] Component Video [Input-2]
S-video
[Input-1]
Video
Audio
RCA pin jack ×3
Y : 1V(p-p), 75 Ω, negative sync
Pb/Pr : 0.7 V(p-p), 75 Ω
Mini DIN 4-pin connector ×1
Y : 1 V(p-p), 75 Ω, negative sync
C : 0.286 V(p-p)(burst signal), 75 Ω
1 V(p-p), 75 Ω, negative sync, RCA pin jack ×2
500 mV(rms)(-4dBs), high impedance, RCA pin jack ×6
Audio Output (Fix) 500 mV(rms)(-4dBs), low Impedance, (400 kHz when modulated 100 %), RCA pin jack ×2
Remote Control Unit RM-C203 (Lithium cell battery ×1)

(No.YA050B)1-3
SECTION 1
PRECAUTION
1.1 SAFETY PRECAUTIONS
(1) The design of this product contains special hardware, 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. Service should be performed by qualified personnel only.
(2) Alterations of the design or circuitry of the products should not be
made. Any design alterations or additions will void the
manufacturer's warranty and will further relieve the manufacturer
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 visualinspectionnor can the protection affordedby 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 Service manual. The use of a substitute replacement
which does not have the same safety characteristics as the
recommended replacement part shown in the parts list of Service
manual may cause shock, fire, or other hazards.
(4) Use isolation transformer when hot chassis.
The chassis and any sub-chassis contained in some products are
connected to one side of the AC power line. An isolation
transformer of adequate capacity should be inserted between the
product and the AC power supply point while performing any
service on some products when the HOT chassis is exposed.
(5) Don't short between the LIVE side ground and ISOLATED (NEU-
TRAL) side ground or EARTH side ground when repairing.
Some model's power circuit is partly different in the GND. The differ-
ence of the GND is shownby the LIVE: ( ) side GND, the ISOLAT-
ED (NEUTRAL) : ( ) side GND and EARTH : ( ) side GND.
Don't short between the LIVE side GND and ISOLATED (NEUTRAL)
side GND or EARTH side GND and never measure the LIVE side
GND and ISOLATED (NEUTRAL) side GND or EARTH side GND at
the same time with a measuring apparatus (oscilloscope etc.). If
above note will not be kept, a fuse or any parts will be broken.
(6) If any repair has been made to the chassis, it is recommended that
the B1 setting should be checked or adjusted (See B1 POWER
SUPPLY check).
(7) The high voltage applied to the picture tube must conform with that
specified in Service manual. Excessive high voltage can cause an
increase in X-Ray emission, arcing and possible component
damage, therefore operation under excessive high voltage
conditions should be kept to a minimum, or should be prevented.
If severe arcing occurs, remove the AC power immediately and
determine the cause by visual inspection (incorrect installation,
cracked or melted high voltage harness, poor soldering, etc.). To
maintain the proper minimum level of soft X-Ray emission,
components in the high voltage circuitry including the picture tube
must be the exact replacements or alternatives approved by the
manufacturer of the complete product.
(8) Do not check high voltage by drawing an arc. Use a high voltage
meter or a high voltage probe with a VTVM. Discharge the picture
tube before attempting meter connection, by connecting a clip lead
to the ground frame and connecting the other end of the lead
through a 10kΩ2W resistor to the anode button.
(9) When service is required, observe the original lead dress. Extra
precaution should be given to assure correct lead dress in the high
voltage circuit area. Where a short circuit has occurred, those
components that indicate evidence of overheating should be
replaced. Always use the manufacturer's replacement
components.
(10) Isolation Check (Safety for Electrical Shock Hazard)
After re-assembling the product, always perform an isolation
check on the exposed metal parts of the cabinet (antenna
terminals, video/audio input and output terminals, Control knobs,
metal cabinet, screw heads, earphone jack, control shafts, etc.) to
be sure the product is safe to operate without danger of electrical
shock.
a) Dielectric Strength Test
The isolation between the AC primary circuit and all metal parts
exposed to the user, particularly any exposed metal part having a
return path to the chassis should withstand a voltage of 1100V AC
(r.m.s.) for a period of one second.
(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rat-
ed up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V
or more, for a period of one second.) This method of test requires
a test equipment not generally found in the service trade.
b) Leakage Current Check
Plug the AC line cord directly into the AC outlet (do not use a line
isolation transformer during this check.). Using a "Leakage
Current Tester", measure the leakage current from each exposed
metal part of the cabinet, particularly any exposed metal part
having a return path to the chassis, to a known good earth ground
(water pipe, etc.). Any leakage current must not exceed 0.5mA AC
(r.m.s.).
However, in tropical area, this must notexceed 0.2mA AC (r.m.s.).
Alternate Check Method
Plug the AC line cord directly into the AC outlet (do not use a
line isolation transformer during this check.). Use an AC
voltmeter having 1000Ωper volt or more sensitivity in the
following manner. Connect a 1500Ω10W resistor paralleled by
a 0.15µF AC-type capacitor between an exposed metal part
and a known good earth ground (water pipe, etc.). 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. Any
voltage measured must not exceed 0.75V AC (r.m.s.). This
corresponds to 0.5mA AC (r.m.s.).
However, in tropical area, this must not exceed 0.3V AC
(r.m.s.). This corresponds to 0.2mA AC (r.m.s.).
(11) High voltage hold down circuit check.
After repair of the high voltage hold down circuit, this circuit shall
be checked to operate correctly.See item "How to check the high
voltage hold down circuit".
AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500 10W
0.15 F AC-TYPE
GOOD EARTH GROUND
PWB
White line side
WHT
PW
POWER CORD
REPLACEMENT WARNING.
Connecting the white line side of power
cord to "WHT" character side.
A V
This mark shows a fast
operating fuse, the
letters indicated below
show the rating.

1-4 (No.YA050B)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
VIDEO STATUS
Expression of a favorite screen can be chosen by the VIDEO
STATUS function.
COMPONENT INPUT
Since the component signal input terminal is equipped, it
reappears direct without deteriorating the signal from DVD.
V-CHIP
Since the V-CHIP is built in, it can choose, view and listen to a
healthy program.
MTS STEREO
The voice multiplex function of the MTS system is built in.
(MTS = Multi channel Television Sound system)
RETURN PLUS
You program a specific channel to return to while scanning
through the channels using the CH+ and CH - keys.
2.2 HOW TO IDENTIFY MODELS
How to recognize from the appearance of the model concerned is written below. Please distinguish from several contents currently
printed on the rating label
AV-27530
MODEL NAME
SCA
DISTINGUISH NAME
MODEL NO.
AC 120V 60Hz
W
TV SCREEN SIZE : DIAGONAL
INCHES
CHASSIS NO.
MANUFACTURED
SERIAL NO.
VIDEO EQUIPMENT
4C43
ME

(No.YA050B)1-5
2.3 TECHNICAL INFORMATION
2.3.1 MAIN MI-COM (CPU) PIN FUNCTION
Pin
No. Pin name I/O Function Pin
No. Pin name I/O Function
1 A_MUTE O Audio muting [Muting : H] 29 YC_GND - GND
2 AFT1 I AFT voltage for tuner (Tuning frequency control) 30 V1_IN I Not used
3 KEY I Key scan for front control [No signal : H] 31 ABCL I Current for automatic beam (brightness)/contrast limit
4 uP_DVss - GND 32
MONITOR_OUT O Not used
5 Reset I CPU reset 33 BLACK_DET - Black level detection filter
6 8MHz_OUT O CPU system clock : 8MHz oscillation 34 SVM_OUT O Y signal for velocity scan modulation
7 8MHz_IN I CPU system clock : 8MHz oscillation 35 APL_FIL - Average picture level filter
8 TEST - GND 36 APC_FIL - Automatic phase control filter
9 uP_DVDD - 5V 37 fsc_OUT O Color sub carrier (3.58MHz) for 3-line digital comb filter [IC5201]
10 AGC_MUTE O AGC muting for tuner (when channel select) [Muting : H] 38 YC_Vcc - 5V (for video process circuit)
11 uP_VVSS - GND 39 R_OUT O R signal
12 TV_HGND - GND 40 G_OUT O G signal
13 FBP_SCP I Flyback pulse (H. pulse) 41 B_OUT O B signal
14 HOUT O H. drive (oscillation) 42 RGB_Vcc - 9V (for RGB process circuit)
15 H_Vcc - 9V (for H. oscillation start) 43 IK_IN I Not used
16 HAFC_1 - H. AFC filter 44 TV_DGND - GND
17 Vsaw - V. saw filter 45 uP_AGND - GND
18 VOUT O V. drive 46 uP_AVdd - 5V
19 EW_OUT O Parabola waveform (for sidepin correection) 47 MAIN_POWER O Power on/off switching control [Powen on : L]
20 X-RAY I X-ray detection (for protection) [Detection : H] 48 HAZARD I Not used
21 Ys I Not used 49 SDAO I/O Data for Inter IC control bus (for various devices)
22 Cb_IN I Cb (external) signal 50 SCLO O Clock for Inter IC control bus (for various devices)
23 Y_IN I Y (external) signal 51 SDA1 I/O Data for Inter IC control bus (for main memory)
24 Cr_IN I Cr (external) signal 52 AGC_ADJUST I AGC adjustment
25 TV_DVcc - 3.3V 53 SCL1 O Clock for Inter IC control bus (for main memory)
26 V3IN/CIN I Chroma signal (for YC separation output) 54 LED O POWER / ON TIMER LED lndication [lighting : L]
27 EHT_IN I Not used 55 REMOCON I Remote control sensor input [No input : H]
28 V2_IN/Y_IN I Y signal (for YC separation output) 56 COMPULINK I Not used