JVC AV-32230/G, AV-32230/H, AV-32230/M, AV-32260/G, AV-32260/H, AV-32260/M Service Manual
SERVICE MANUAL
COLOR TELEVISION
AV-32230
AV-32260
BASIC CHASSIS
AC
AV-32230
AV-32230
AV-32230
TVTV
RM-C306
[AV-32230]
RM-C305
[AV-32260]
/G
/H
/M
AV-32260
AV-32260
AV-32260
/G
/H
/M
CONTENTS
a SPECIFICATIONS ....................................................................................................................................2
a SAFETY PRECAUTIONS ........................................................................................................................3
a FEATURES ..............................................................................................................................................5
a MAIN DIFFERENCE LIST........................................................................................................................6
a HOW TO IDENTIFY MODELS ..................................................................................................................6
a FUNCTIONS .............................................................................................................................................7
a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................8
a SERVICE ADJUSTMENTS ....................................................................................................................13
¤ STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1
a PARTS LIST ...........................................................................................................................................35
Design & specifications are subject to change without notice.
2No. 51802
GOOD
EARTH
GROUND
0.15 µF AC-TYPE
AC VOLTMETER
(HAVING 1000Ø/V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500Ø 10W
A V
This mark shows a fast
POWER CORD
REPLACEMENT WARNING
Connecting thr white line side of
power cord to “WHT” character side.
operating fuse, the
letters indicated below
show the rating.
PWB
WHT
PW
White line side
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 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 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 difference of the GND is shown by the LIVE : ( ) side GND, the
ISOLATED(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 with a measuring apparatus (oscilloscope etc.) the LIVE
side GND and ISOLATED(NEUTRAL) side GND or EARTH side
GND at the same time.
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 ADJUSTMENT
OF B1 POWER SUPPLY).
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 10kØ 2W 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.
No. 518023
AV-32230
AV-32260
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,
screwheads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.
(1) 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 rated
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.
(2) 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 not exceed 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 1000 ohms per volt or more sensitivity in the following manner.
Connect a 1500Ø 10W 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”.
AV-32230
AV-32260
REPLACEMENT OF CHIP COMPONENT
CAUTIONS
a
1. Avoid heating for more than 3 seconds.
2. Do not rub the electrodes and the resist parts of the pattern.
3. When removing a chip part, melt the solder adequately.
4. Do not reuse a chip part after removing it.
SOLDERING IRON
a
1. Use a high insulation soldering iron with a thin pointed end of it.
2. A 30w soldering iron is recommended for easily removing parts.
REPLACEMENT STEPS
a
1. How to remove Chip parts
Resistors, capacitors, etc.
(1) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each end.
2. How to install Chip parts
Resistors, capacitors, etc.
(1) Apply solder to the pattern as indicated in the figure.
(2) Shift with tweezers and remove the chip part.
Transistors, diodes, variable resistors, etc.
(1) Apply extra solder to each lead.
SOLDER
(2) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each lead. Shift and remove the chip
part.
SOLDER
(2) Grasp the chip part with tweezers and place it on the solder.
Then heat and melt the solder at both ends of the chip part.
Transistors, diodes, variable resistors, etc.
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the solder.
(3) First solder lead A as indicated in the figure.
A
B
C
(4) Then solder leads B and C.
A
Note : After removing the part, remove remaining solder from the
pattern.
4No. 51802
B
C
FEATURES
Full-square CRT (cathode ray tube) reproduces fine textured pic-
•
ture in every detail.
I2C bus control utilizes single chip ICs.
•
Built in Twin Tuner system. [Only for AV-32260 model]
•
Built-in HYPER-SURROUND system.
•
Adoption of the Picture-In-Picture (PIP) function. [Only for AV-32260
•
model]
a SYSTEM BLOCK DIAGRAM
AV-32230
AV-32260
3 LINE DIGITAL COMB FILTER circuit improved picture quality.
•
Component input terminal for talking best advantage of Component
•
Video Signal.
Audio Video input terminal. (S-input ×1, V-input ×2)
2. Remove the 11 screws marked A as shown in Fig.1.
3. Withdraw the REAR COVER toward you.
[CAUTION]
When reinstalling the rear cover, carefully push it inward after in-
•
serting the MAIN PWB into the rear cover groove.
REMOVING THE CHASSIS
After removing the rear cover.
•
1. Slightly raise the both sides of the chassis by hand and remove the
3 claws marked B under the chassis from the front cabinet as
shown in Fig.1.
2. Withdraw the chassis backward along the rail in the arrow direction
marked C as shown in Fig.1.
(If necessary, take off the wire clamp, connector’s etc.)
When conducting a check with power supplied, be sure to confirm
*
that the CRT earth wire is connected to the CRT SOCKET PWB
and the MAIN PWB.
REMOVING THE TERMINAL BOARD
After removing the rear cover.
•
1. Remove the 4 screws marked D as shown in Fig.1.
2. When you pull out the TERMINAL BOARD in the direction of arrow
marked E as shown in Fig.1, it can be removed.
REMOVING THE SPEAKER
After removing the rear cover.
•
1. Remove the 2 screws marked K as shown in Fig.1.
2. Withdraw the speaker backward.
3. Follow the same steps when removing the other hand speaker.
CHECKING THE MAIN PW BOARD
1. To check the back side of the MAIN PW Board.
1) Pull out the chassis. (Refer to REMOVING THE CHASSIS).
2) Erect the chassis vertically so that you can easily check the back
side of the MAIN PW Board.
[CAUTION]
When erecting the chassis, be careful so that there will be no con-
•
tacting with other PW Board.
Before turning on power, make sure that the CRT earth wire and
•
other connectors are properly connected.
WIRE CLAMPING AND CABLE TYING
1. Be sure clamp the wire.
2. Never remove the cable tie used for tying the wires together.
Should it be inadvertently removed, be sure to tie the wires with a
new cable tie.
REMOVING THE FRONT CONTROL AND FRONT AV
INPUT PW BOARDS
After removing the rear cover and chassis.
•
1. Remove the 2 screws marked F and the 2 screws marked G as
shown in Fig.1.
2. Then remove the FRONT CONTROL PWB and FRONT AV INPUT
PWB.
(If necessary, take off the wire, connector’s etc.)
REMOVING THE LF PW BOARD
After removing the rear cover and chassis.
•
1. Lift the left side of the LF PWB while pressing the 2 PWB stoppers
marked H in the arrow direction marked J as shown in Fig.1.
2. Then remove the LF PWB.
(If necessary, take off the wire, connector’s etc.)
8No. 51802
FRONT AV INPUT PWB
PWB
STOPPER
A
MAIN PWB
LF PWB
CRT SOCKET PWB
PICTURE TUBE
FRONT
CONTROL PWB
AV SELECTOR
PWB
CHASSIS BASE
PIP PWB (Only for AV-32260 model)
SPEAKER
FRONT CABINET
REAR COVER
K
F
(x2)
(x2)
G
(x2)
(x11)
(x2)
K
D
(x4)
E
C
J
CLAW
B
H
CLAW
B
AV-32230
AV-32260
Fig.1
No. 518029
AV-32230
AV-32260
REMOVING THE CRT
* Replacement of the CRT should be performed by 2 or more persons.
After removing the rear cover, chassis etc.,
•
1. Putting the CRT change table on soft cloth, the CRT change table
should also be covered with such soft cloth (shown in Fig.2).
2. While keeping the surface of CRT down, mount the TV set on the
CRT change table balanced will as shown in Fig.3.
3. Remove 4 screws marked by arrows with a box type screwdriver as
shown in Fig.3.
Since the cabinet will drop when screws have been removed, be
•
sure to support the cabinet with hands.
4. After 4 screws have been removed, put the cabinet slowly on cloth
(At this time, be carefully so as not to damage the front surface of the
cabinet) shown in Fig.4.
The CRT should be assembled according to the opposite sequence
•
of its dismounting steps.
* The CRT change table should preferably be smaller that the CRT sur-
face, and its height be about 35cm.
CRT CHANGE TABLE
CLOTH
CRT
CHANGE
TABLE
Fig. 2
CRT
APPROX.
35cm
BOX
TYPE
SCREW
DRIVER
COATING OF SILICON GREASE FOR ELECTRICAL INSULATION ON THE CRT ANODE CAP SECTION.
Subsequent to replacement of the CRT and HV transformer or repair
•
of the anode cap, etc. by dismounting them, be sure to coat silicon
grease for electrical insulation as shown in Fig.5.
Wipe around the anode button with clean and dry cloth. (Fig.5)
Coat silicon grease on the section around the anode button. At this
time, take care so that any silicon greases dose not sticks to the
anode button. (Fig.6)
夝 Silicon grease product No. KS - 650N
CRT
Anode button
CABINET
Approx.
20mm (Do not
coat grease on
this section
Fig. 3
Fig. 4
CRT
CRT
CHANGE TABLE
Silicon grease
should be coated
by 5mm or more
from the outside
diameter of anode
cap.
Silicon grease
coating
Fig. 5
10No. 51802
Anode button
(No sticking of
silicon grease)
Fig. 6
Coating position
of silicon grease
Anode cap
MEMORY IC REPLACEMENT
1. Memory IC
This model use a memory IC.
This memory IC stores data for proper operation of the video and deflection circuits.
When replacing, be sure to use an IC containing this (initial value) data.
2. Memory IC replacement procedure
ProcedureScreen display
(1) Power off
Switch off the power and disconnect the power cord from the outlet.
(2) Replace the memory IC
Initial value must be entered into the new IC.
(3) Power on
Connect the power cord to the outlet and switch on the power.
AV-32230
AV-32260
(4) System constant check and setting
1) Press SLEEP TIMER key and, while the indication of “SLEEP TIMER
0 MIN.” is being displayed, press DISPLAY key and VIDEO STATUS
key on the remote control unit simultaneously.
2) The SERVICE MENU screen of Fig.1 is displayed.
3) While the SERVICE MENU is displayed, again simultaneously press
the DISPLAY and VIDEO STATUS keys to display the Fig.2 SYSTEM
CONSTANT screen.
4) Refer to the SYSTEM CONSTANT table and check the setting items.
Where these differ, select the setting item with the MENU UP/DOWN
key and adjust the setting with the MENU LEFT/RIGHT keys. (The
letters of the selected item are displayed in yellow.)
5) After adjusting, release the MENU LEFT/RIGHT key to store the
setting value.
6) Press the EXIT key twice to return the normal screen.
(5) Receive channel setting
Refer to the OPERATING INSTRUCTIONS(USER'S GUIDE) and set the
receive channels (Channels Preset) as described.
(6) User settings
Check the user setting items according to Table 2.
Where these do not agree, refer to the OPERATING INSTRUCTIONS (USER'S GUIDE) and set the items as described.
(7) SERVICE MENU setting
Verify what to set in the SERVICE MENU, and set whatever is
necessary.(Fig.1) Refer to the SERVICE ADJUSTMENT for setting.