JVC AV-28X37SUE User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD. No.52106
2003/03
AV-28X37SUE AV-28X37HKE
AV-28X35HKE AV-28X37HIE
AV-28H35SUE AV-28H35BUE
AV-28X35HUE
COLOUR TELEVISION
52106200303 AV-28X37SUE, AV-28X37HKE,
AV-28X35HKE, AV-28X37HIE,
AV-28H35SUE, AV-28H35BUE,
AV-28X35HUE
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
AV-28X37SUE
AV-28X37HKE
AV-28X37HIE
AV-28X35HKE
AV-28H35SUE
AV-28H35BUE
AV-28X35HUE
<RM-C50H>
<RM-C54H>
<RM-C55H>
1 2 3
4 5 6
7 8 9
0
P
AV
TV OK
MENU
P
TV
BASIC CHASSIS
ML

AV-28X37SUE AV-28X37HKE
AV-28X35HKE AV-28X37HIE
AV-28H35SUE AV-28H35BUE
AV-28X35HUE
1-2 (No.52106)
SPECIFICATION
Design & specifications are subject to change without notice.
Item Content
AV-28H35SUE
AV-28H35BUE AV-28X37SUE AV-28X35HUE AV-28X37HKE AV-28X35HKE AV-28X37HIE
Dimensions ( W x H x D )
85.4cm x 50.8cm x 49cm 85.4cm x 50.8cm x 49.3cm
Mass 36.3kg 39.0kg
TV RF System CCIR (B/G, D/K, I , L/L') CCIR (I)
Colour System PAL / SECAM / NTSC (Only in EXT mode) PAL
Stereo System A2 (B/G, D/K) / NICAM (B/G, I, D/K, L) NICAM (I)
Teletext System FLOF (Fastext)
TOP (German system)
WST(World standard system)
FLOF (Fastext)
WST(World standard system)
Receiving
Frequency VHF 47MHz ~ 470MHz Not avairable 47MHz ~ 470MHz
UHF 470MHz ~ 862MHz
Frenc CATV 116MHz ~ 172MHz / 220MHz ~ 469MHz -
Intermediate
Frequency VIF Carrier 38.9MHz (B/G, D/K, I , L) / 33.95MHz (L') 38.9MHz (I)
SIF Carrier 33.4MHz (5.5MHz:B/G)
/ 32.9MHz (6.0MHz:I)
/ 32.4MHz (6.5MHz:L, D/K)
/ 40.45MHz (6.5MHz:L')
32.9MHz (6.0MHz:I)
Colour Sub
Carrier Frequency PAL 4.43MHz
SECAM 4.40625MHz / 4.25MHz -
NTSC 3.58MHz / 4.43MHz 3.58MHz
Power Input AC220V ~ AC240V, 50Hz
Power Consumption 185W(Max) / 115W(Avg), standby : 2.5W
Aerial Input Terminal 75ohm unbalanced, coaxial
Picture Tube Visible size : 66cm, Measured diagonally H : 58.3cm x V : 33.0cm
High Voltage 31.0kV (+1kV / -1.5kV) (CRT cutoff, FULL mode)
Speaker 13cm x 6.5cm oval type x 2
Audio Power Output 10W + 10W
EXT-1 / EXT-2 / EXT-3
(Input / Output) 21-pin Euro connector (SCART socket)
EXT-4 (Input) Video 1V(p-p) 75ohm (RCA pin jack)
Audio (L/R) 500mV(rms) (-4dBs), High impedance (RCA pin jack)
S-Video Y : 1V(p-p) positive (negative sync provided, when terminated with 75ohm )
C : 0.3V(p-p) (Burst signal, when terminated with 75ohm )
AUDIO OUT (Variable) 0~1000mV(rms), Low impedance (RCA pin jack x 2)
Headphone Jack Stereo mini jack (Ø3.5mm )
Remote Control Unit RM-C54H (AAA/R03 dry battery x 2)
[Exept AV-28H35BUE]
RM-C50H (AAA/R03 dry battery x 2)
[Only AV-28H35BUE]
RM-C55H (AAA/R03 dry battery x 2)

AV-28X37SUE AV-28X37HKE
AV-28X35HKE AV-28X37HIE
AV-28H35SUE AV-28H35BUE
AV-28X35HUE
(No.52106)1-3
21-pin Euro connector (SCART) : EXT-1/EXT-2/EXT-3
(P-P= Peak to Peak, B-W= Blanking to white peak)
PinNo. Signal Designation Matching Value EXT-1 EXT-2 PinNo. EXT-3
1 AUDIO R output 500mV(rms) (Nominal),
Low impedance Used (TV OUT) Used (LINE OUT) 22 NC
2 AUDIO R input 500mV(rms) (Nominal),
High impedance Used (R1) Used (R2) 23 Used (R3)
3 AUDIO L output 500mV(rms) (Nominal),
Low impedance Used (TV OUT) Used (LINE OUT) 24 Not used
4 AUDIO GND Used Used 25 Used
5 GND (B) Used Used 26 Used
6 AUDIO L input 500mV(rms) (Nominal),
High impedance Used (L1) Used (L2) 27 Used (L3)
7 B input 700mV(B-W), 75 ohm Used Used 28 Not used
8 FUNCTION SW
(SLOW SW) Low : 0V-3V, High : 8V-12V, High impedance Used Used 29 Used
9 GND (G) Used Used 30 Used
10 SCL / T-V LINK Not used Used (SCL2
/ TV-LINK) 31 Not used
11 G input 700mV(B-W), 75 ohm Used Used 32 Not used
12 SDA Not used Used(SDA2) 33 Not used
13 GND (R) Used Used 34 Used
14 GND (YS) Used Not used 35 Not used
15 R / C input R : 700mV(B-W), 75 ohm
C : 300mV(P-P), 75 ohm Used (R) Used (C2/R) 36 Used (C3)
16 Ys input
(FAST SW) Low : 0V-0.4V, High : 1V-3V, 75 ohm Used Used 37 Not used
17 GND (VIDEO output) Used Used 38 Used
18 GND (VIDEO input) Used Used 39 Used
19 VIDEO output 1V(P-P) (Negative sync),
75 ohm Used (TV OUT) Used (LINE OUT) 40 Not used
20 VIDEO / Y input 1V(P-P) (Negative sync),
75 ohm Used Used 41 Used
21 COMMON GND Used Used 42 Used
20 18 16 14 12 10 8 6 4 2
21 19 17 15 13 11 9 7 5 3 1
[Pin assignment]

AV-28X37SUE AV-28X37HKE
AV-28X35HKE AV-28X37HIE
AV-28H35SUE AV-28H35BUE
AV-28X35HUE
1-4 (No.52106)
SECTION 1
PRECAUTIONS
1.1 SAFETY PRECAUTIONS [EXCEPT FOR UK]
(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) Don’t short between the LIVE side ground and
ISOLATED (NEUTRAL) 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 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.
(5) 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).
(6) 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.
(7) 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 10k
2W resistor to the anode button.
(8) 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.
(9) 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 3000V 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.
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 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 1500 ohm
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
0.75VAC(r.m.s.).Thiscorrespondsto0.5mAAC(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.).
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

AV-28X37SUE AV-28X37HKE
AV-28X35HKE AV-28X37HIE
AV-28H35SUE AV-28H35BUE
AV-28X35HUE
(No.52106)1-5
1.2 SAFETY PRECAUTIONS [FOR UK]
(1) The 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. Service should be performed by qualified personnel
only.
(2) Alterations of the design or circuitry of the product 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 product have special safety-related characteristics. These characteristics are often
not evident from visual inspection nor can the protection afforded by them necessary 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 part shown in the Parts List of Service Manual may cause 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.
WARNING
(1) The 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.