In the interests of user-safety (Required by safety regulations in some countries ) the set should be restored to its
original condition and only parts identical to those specified should be used.
25VT-CK10
CONTENTS
Page
æ IMPORTANT SERVICE SAFETY PRECAUTION .....................................................................................2
æ REPLACEMENT PARTS LIST................................................................................................................51
æ PACKING OF THE SET..........................................................................................................................70
(Refer to 13VT-J100 Service Manual)
(Refer to 13VT -J100 Ser vice Manual)
(Refer to 13VT-J100 Service Manual)
(Refer to 13VT-J100 Service Manual)
(Refer to 13VT-J100 Service Manual)
SHARP CORPORATION
This document has been published to be used for
after sales service only.
The contents are subject to change without notice.
1
25VT-K100
25VT-CK10
IMPORTANT SERVICE SAFETY PRECAUTION
Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and servicing guidelines which follow:
WARNING
1. For continued safety, no modification of any circuit
should be attempted.
2. Disconnect AC power before servicing.
3. Semiconductor heat sinks are potential shock
hazards when the chassis is operating.
4. The chassis in this receiver has two ground systems
which are separated by insulation material. The nonisolated (hot) ground system is for the B+ voltage
regulator circuit and the horizontal output circuit.The
isolated ground system is for the low B+ DC voltages
and the secondary circuit of the high voltage
transformer.
To prevent electrical shock use an isolation
transformer between the line cord and power
receptacle, when servicing this chassis.
CAUTION: FOR CONTINUED
PROTECTION AGAINST A
RISKOF FIRE, REPLACE
4A 125V
ONLY WITH SAME TYPE 4A125V FUSE.
SERVICING OF HIGH VOLTAGE SYSTEM
AND PICTURE TUBE
When servicing the high voltage system, remove the static charge by connecting a 10k
ohm resistor in series with an insulated wire
(such as a test probe) between the picture
tube ground and the anode lead. (AC line
cord should be disconnected from AC outlet.)
1. Note that the picture tube in this receiver employs
integral implosion protection.
2. Replace with tube of the same type number for
continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing
shatterproof goggles and after discharging the high
voltage anode completely.
X-RADIATION AND HIGH VOLTAGE LIMITS
1. Be sure all service personnel are aware of the
procedures and instructions covering X-radiation. The
only potential source of X-ray in current solid state
TV receivers is the picture tube. However , the picture
tube does not emit measurable X-Ray radiation if the
high voltage is as specified in the "High Voltage
Check" instructions.
It is only when high voltage is excessive that Xradiation is capable of penetrating the shell of the
picture tube including the lead in glass material. The
important precaution is to keep the high voltage below
the maximum level specified.
2. It is essential that servicepersonal have available at
all times an accurate high voltage meter.
The calibration of this meter should be checked
periodically.
3. High voltage should always be kept at the rated value
−no higher. Operation at higher voltages may cause
a failure of the picture tube or high voltage circuitry
and; also under certain conditions, may produce
radiation excess specitications.
4. When the high voltage regulator is operating properly
there is no possibility of an X-radiation problem. Every
time a color chassis is serviced, the brightness
should be tested while monitoring the high voltage
with a meter to be certain that the high voltage does
not exceed the specified value and that it is regulating
correctly .
5. Do not use a picture tube other than that specified or
make unrecommended circuit modifications to the
high voltage circuitry.
6. When trouble shooting and taking test measurements
on a receiver with excessive high voltage, avoid being
unnecessarily close to the receiver.
Do not operate the receiver longer than is necessary
to locate the cause of excessive voltage.
2
2
2
2
IMPORTANT SERVICE SAFETY PRECAUTION
(Continued)
25VT-K100
25VT-CK10
BEFORE RETURNING THE RECEIVER
(Fire & Shock Hazard)
Before returning the receiver to the user, perform
the following safety checks.
1. Inspect all lead dress to make certain that leads are
not pinched or that hardware is not lodged between
the chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic
control knobs, insulating materials, cabinet backs,
adjustment and compartment covers or shields,
isolation resistor-capacity networks, mechanical
insulators, etc.
3. To be sure that no shock hazard exists, check for
leakage current in the following manner.
» Plug the AC cord directly into a 120 volt AC outlet,
using reverse polarity (Do not use an isolation
transformer for this test).
» Using to clip leads, connect a 1.5k ohm, 10 watt
resistor paralleled by a 0.15µF capacitor in series
with all exposed metal cabinet parts and a known
earth ground, such as electrical conduit or electrical
ground connected to earth ground.
» Use an AC voltmeter having with 5000 ohm per volt,
or higher, sensitivity to measure the AC voltage drop
across the resistor.
» Connect the resistor connection to all exposed metal
parts having a return to the chassis
(antenna, metal cabinet, screw heads, knobs and
control shafts, escutcheon, etc.) and measure the AC
voltage drop across the resistor.
AII check must be repeated with the AC line cord
plug connection reversed. (IF necessary, a nonpolarized adapter plug must be used only for the
purpose of completing these check.)
Any current measured must not exceed 0.5 milliamp.
Any measurements not within the limits outlined
above are indicative of a potential shock hazard and
corrective action must be taken before returning the
instrument to the customer.
Many electrical and mechanical parts in television
receivers have special safety-related characteristics.
These characteristics are often not evident from visual
inspection, nor can protection afforded by them be
necessarily increased by using replacement components
rated for higher voltage, wattage, etc.
Replacement parts which have these special
safety characteristics are identified in this manual;
electrical components having such features are identified
by " å " and shaded areas in the Replacement Parts
Lists and Schematic Diagrams.
For continued protection, replacement parts must be
identical to those used in the original circuit. The use of
a substitute replacement parts which do not have the
same safety characteristics as the factory recommended
replacement parts shown in this service manual, may
create shock, fire, X-radiation or other hazards.
3
25VT-K100
25VT-CK10
PRECAUTIONS A PRENDRE LORS DE LA REPARATION
Ne peut effectuer la réparation qu' un technicien spécialisé qui s'est parfaitement
accoutumé à toute vérification de sécurité et aux conseils suivants.
AVERTISSEMENT
1. N'entreprendre aucune modification de tout circuit.
C'est dangereux.
2. Débrancher le récepteur avant toute réparation.
3. Les déversoirs thermiques à semi-conducteurs
peuvent présenter un danger de choc électrique
lorsque le réceqteur est en marche.
4. Le châssis de ce récepteur a deux systèmes de mise
à la terre qui sont séparés par un matériau isolant.
Le système de mise à la terre non-isolée (chaud) est
pour le circuit du régulateur de tension B+ et le circuit
de sortie horizontale. Le système de mise à la terre
isolé est pour les basses tensions C. C. B+ et le circuit
secondaire du transformateur de haute tension.
PRECAUTION:POUR LA
PROTECTION CONTINUE
CONTRE LES RISQUES
4A 125V
D'INCENDIE, REMPLACER LE
FUSIBLE PAR UN FUSIBLE DE
MEME TYPE 4A-125V.
REPARA TION DU SYSTEME A HAUTE TENSION ET DU TUBE-IMAGE
Lors de la réparation de ce systéme,
supprimer la charge statique en branchant
une résistance de 10 kΩ en série a vec un fil
isolé (comme une sonde d'essai) entre la
mise à la terre du tube-image et le fil
d'anodel. (Le cor den d'alimentation doit être
retiré de la prise murale.)
1. Il est à noter que le tube-image de ce récepteur est
intégralement protégé contre l'implosion.
2. Par mesure de sécurité, changer le tube-image pour
un tube du même numéro de type.
3. Ne pas lever le tube-image par son col.
4. Ne manipuler le tube-image qu'en porant des lunettes
incassables et qu'après avoir déchargé totalement
la haute tension.
LIMITES DES RADIATIONS X ET DE LA
HA UTE TENSION
1. Tout le personnel réparateur doit être instruit des
instructions et procédés relatifs aux radiations X.
Le tube-image, seule source de rayons X dons les
téleviseurs transistorisés, n'émet pourtant pas de
rayons mesurables si la haute tension est maintenue
à un niveau préconisé dans la section "Vérification
de la haute tension".
C'est seulement quand la haute tension est excessive
que les rayons X peuvent entrer dans l'enveloppe du
tube-image y compris le conducteur de verre. Il est
important de maintenir la haute tension en-dessous
du niveau spécifié.
2. Il est essentiel que le réparateur ait sous la main un
voltmètre à haute tension qui doit être périodiquement
étalonné.
3. La haute tension doit toujours être maintenue à la
valeur de régime-et pas plus haute. L'opération à des
tensions plus élevées peut entraîner une panne du
tube-image ou du circuit à haute tension et, dans
certaines conditions, peut entraîner une radiation
dépassant les niveaux préscrits.
4. Quand le régulateur à haute tension fonctionne
correctement, il n'y a aucun problème de radiation
X. Chaque fois qu'un châssis couleurs est réparé, la
luminosité doit être examinée bout en contrôlant la
haute tension à l'aide d'un voltmètre pour s'assurer
que la haute tension ne dépasse pas la valeur
spécifiée et qu'elle soit correctement réglée.
5. Ne pas utiliser un tube-image autre que celui spécifié
et ne pas effectuer de modifications déconseillées
du circuit à haute tension.
6. Lors de la recherche des pannes et des mesures
d'essai sur un récepteur qui présente une haute
tension excessive, éviter de s'approcher inutilement
du récepteur.
Ne pas faire fonctionner le récepteur plus longtemps
que nécessaire pour localiser la cause de la tension
excessive.
4
25VT-K100
22
25VT-CK10
PRECAUTIONS A PRENDRE LORS DE LA REPARATION
(Suite)
VERIFICATIONS CONTRE L'INCEN-DIE ET
LE CHOC ELECTRIQUE
Avant de rendre le récepteur à l'utilisateur, effectuer
les vérifications suivantes.
1. Inspecter tous les faisceaux de câbles pour s'assurer
que les fils ne soient pas pincés ou qu'un outil ne soit
pas placé entre le châssis et les autres pièces
métalliques du récepteur.
2. Inspecter tous les dispositifs de protection comme
les boutons de commande non-métalliques, les
isolants, le dos du coffret, les couvercles ou blindages
de réglage et de compartiment, les réseaux de
résistance-capacité, les isolateurs mécaniques, etc.
3. S'assurer qu'il n'y ait pas de danger d'électrocution
en vérifiant la fuite de courant, de la facon suivante:
» Brancher le cordon d'alimentation directem-ent à une
prise de courant de 120V. (Ne pas utiliser de
transformateur d'isolation pour cet essai).
» A l'aide de deux fils à pinces, brancher une résistance
de 1,5 kΩ 10 watts en parallèle avec un condensateur
de 0,15µF en série avec toutes les pièces métalliques
exposées du coffret et une terre connue comme une
conduite électrique ou une prise de terre branchée à
la terre.
» Utiliser un voltmètre CA d'une sensibilité d'au moins
5000Ω/V pour mesurer la chute de tension en travers
de la résistance.
» Toucher avec la sonde d'essai les pièces métalliques
exposées qui présentent une voie de retour au
châssis (antenne, coffret métallique, tête des vis,
arbres de commande et des boutons, écusson, etc.)
et mesurer la chute de tension CA en-travers de la
résistance.
Toutes les vérifications doivent être refaites après
avoir inversé la fiche du cordon d'alimentation. (Si
nécessaire, une prise d'adpatation non polarisée peut
être utilisée dans le but de terminer ces vérifications.)
Tous les courants mesurés ne doivent pas dépasser
0,5 mA.
Dans le cas contraire, il y a une possibilité de choc
électrique qui doit être supprimée avant de rendre le
récepteur au client.
De nombreuses pièces, électriques et mécaniques, dans
les téléviseurs présentent des caractéristiques spéciales
relatives à la sécurité, qui ne sont souvent pas évidentes
à vue. Le degré de protection ne peut pas être
nécessairement augmentée en utilisant des pièces de
remplacement étalonnées pour haute tension,
puissance, etc.
Les pièces de remplacement qui présentent ces
caractéristiques sont identifiées dans ce manuel; les
pièces électriques qui présentent ces particularités sont
identifiées par la marque " å " et hachurées dans la
liste des pièces de remplacement et les diagrammes
schématiques.
Pour assurer la protection, ces pièces doivent être
identiques à celles utilisées dans le circuit d'origine.
L'utilisation de pièces qui n'ont pas les mêmes
caractéristiques que les pièces recommandées par
l'usine, indiquées dans ce manuel, peut provoquer des
électrocutions, incendies, radiations X ou autres
accidents.
5
25VT-K100
25VT-CK10
VHF/UHF ANTENNA INPUT IMPEDANCE:75 ohm unbalanced
ELECTRICAL SPECIFICATIONS
TV SECTION
POWER INPUT:120 V AC 60 Hz
POWER RATING:110W
PICTURE SIZE
Width:63.4cm
Height:58.8cm
Depth:51.2cm
CONVERGENCE:Magnetic
SWEEP DEFLECTION:Magnetic
FOCUS:Hi-Bi-Potential Electrostatic
INTERMEDIATE FREQUENCIES
Picture IF Carrier Frequency:45.75 MHz
Sound IF Carrier Frequency:41.25 MHz
Color Sub-Carrier Frequency:42.17 MHz (Nominal)
AUDIO POWER OUTPUT RATING:1.3W (at 10% Distortion)
SPEAKER
Size:8cm (3")P.M.,0.34 oz. Magnet
V oice Coil Impedance:8 ohm at 400 Hz
TUNING RANGES
VHF-Channels:2 thru 13
UHF -Channels:14 thru 69
CATV Channels:1,14 thru 125 (EIA,Channel Plan)
VCR SECTION
Maximum Recording Time:(SP)160min (T-160)
Format:VHS Standard
Video Recording System:Rotary Two-Head Helical Scanning
Number of Video Heads:2 pcs.
Video Signal Standard:NTSC Color System
Tape Width:12.7mm (1/2inch)
Tape Speed:(SP)33.35mm/sec (1.31i.p.s)
(LP)16.67mm/sec (0.66i.p.s)
Play back only
(EP)11.12mm/sec (0.44i.p.s)
(EP)480min (T-160)
Video Input:0.5 to 2.0 Vp-p, 75 ohm unbalanced
Audio Input:-8dB, 47k ohm unbalanced (0 dB-0.775 Vrms)
Operating Temperature:5°C to 40°C (41°F to 104°F)
Storage Temperature:-20°C to 60°C (-4°F to 140°F)
Specifications are subject to change without prior notice.
6
LOCATION OF USER'S CONTROL
25VT-K100
25VT-CK10
7
25VT-K100
25VT-CK10
LOCATION OF USER'S CONTROL (Continued)
Location Of Control’s Buttons (Remote Control)
8
25VT-K100
25VT-CK10
DISASSEMBLY AND REASSEMBLY
1. Remove the 6 rear cover fixing screws and detach the rear cover.
2. Take out the anode cap, CRT PWB, connectors K,M and RC, coating ground SP chip, fixing screws and others.
3. Remove the 2 main PWB fixing screws and take out the main PWB unit and the VCR unit.
4. Remove the 7 VCR fixing screws, and detach the shielding case.
9
25VT-K100
25VT-CK10
DISASSEMBLY AND REASSEMBLY (Continued)
5. Remove the 4 cassette housing control fixing screws, and detach the cassette housing control.
6. Remove the 4 mechanism chassis fixing screws, and detach the mechanism chassis PWB.
7. Remove the 8 main PWB fixing screws, and detach the main PWB.
10
25VT-K100
25VT-CK10
DISASSEMBLY AND REASSEMBLY (Continued)
For servicing any of the components inside, disconnect the lead dressing holder. Position the main PWB unit upright
as shown below and connect the leads for starting the services.
Note: Fit the VCR unit into the front cabinet with the
front flap door tilted at 70~80°.
70~80°
11
25VT-K100
25VT-CK10
INSTALLATION AND SERVICE INSTRUCTIONS
Notes: (1) When performing any adjustments to resistor controls and transformers use non-metallic
screwdriver or TV alignment tools.
(2) Before performing adjustment, TV set must be on at least 15 minutes.
CIRCUIT PROTECTION
The receiver is protected by a 4.0A fuse (F701), mounted
on PWB-A, wired into one side of the AC line input.
X-RADIATION PROTECTOR CIRCUIT TEST
After service has been performed on the horizontal
deflection system, high voltage system, or B+ system,
test the X-radiation protector circuit to ascertain proper
operation as follows:
1. Apply 120V AC using a variac transformer for
accurate input voltage.
2. Allow for warm up and using the remote controller,
set the brightness level and contrast level to
maximum.
3. Check the voltage of test point TP653. (It’s voltage
should be about 10.5V DC.)
4. Apply external 13.5V DC at TP653 by using an
external DC supply , The increased voltage will cause
the horizontal oscillator to stop and the TV to shut
off.
5. To re-start the osillator, remove the external DC
power supply and short together TP651 and TP652.
Once the TV set operates normally again, remove
the short between TP651 and TP652.
HIGH V OL T A GE CHECK
High voltage is not adjustable but must be checked
to verify that the receiver is operating within safe
and efficient design limitations as specified checks
should be as follows:
1. Connect an accurate high voltage meter between
ground and anode.
2. Operate receiver for at least 15 minutes at 120V AC
line voltage, with strong air signal or properly tuned
in test signal.
3. Set to Service mode on, service item: MUTE, and
bus data 1(Y-mute on).
4. The voltage should be approximately 28.1kV (at zero
beam).
If a correct reading cannot be obtained, check
circuitry for malfunctioning components.
Upon completion of voltage check, readjust screen
control for proper operation and set S851 to center
position (cut off mode).
12
25VT-K100
SERVICEMODE:01SUB-COLOR=64
25VT-CK10
The SHARP TV/VCR COMBINATION have most of the analog setup adjustments eliminated. Coil and variable
resistor adjustments are now performed digitally by using the remote transmitter or set’s volume and channel
change function buttons.
Note: There are still a few analog adjustments in the J-series such as 120V adjust, focus, master screen
voltage and coils in the picture if/detector circuit.
Follow the steps below whenever service adjustment is required. See table “B” to determine if service
adjustments are required.
1.Service mode -
Before putting unit into the service mode, check, that
customer adjustments are in the normal mode. use
the reset function in the video adjust menu to ensure
customer controls are in their proper ( reset ) position.
To enter the service mode -
While pressing the Ch-up (S2507) button, Plug the
AC cord into a wall socket. Now the TV set is switched
on and enters the service mode.
When successfully entered, the service mode will be
displayed as shown in Figure A. The “SERVICE
MODE” figure the top line stands for service
adjustment item and data (see Figure A.).
To exit service mode-
Turn off the power or unplug the set.
2. Service item selection
Once in the service mode, press the channel up or
channel down button on the remote transmitter or at
the set.
(Table-A.) . Select the item you wish to adjust.
3.Data number selection
Pess the volume up or down button to adjust the data
number in the upper left hand side of the screen.
PICTURE:16
Figure A.
02
13
25VT-K100
25VT-CK10
Table-A
ADJUSTMENT
ITEM
PICTURE160~63
TINT390~77
COLOR130~63
BRIGHT320~63
SHARP70~13
V -PHASE00~7
H-PHASE200~31
RF-AGC320~63
V-AMP320~63
PIF-VCO400~127
R CUT-OFF00~255
G CUT -OFF00~255
B CUT-OFF00~255
G GAIN1280~255
B GAIN1280~255
MUTE00~2"0"=Normal raster,"1"=no Y "2"=No Vertical
BALANCE320~63
TEXT POSITION280~128
TEXT PICTURE200~1
CCD LEVEL70~10
OPTION10~3
INTIAL VALUERANGE
DATA
ADJUSTMENT
COMMENTS
*No adjustment is required due to proper setting being made by IC3101 automatically.
Table-B
PART
REPLACED
IC2001X
IC401X
IC2101X
CRTX
NECESSARYUNNECESSARY
ADJUSTMENT
NOTE
Data is stored in IC2101.
The adjustment is needed to compensate for characteristics
of parts including IC401.
Initial setting values are written from IC2001.Adjust for best
results.
Adjust items related to picture tube only.
14
25VT-K100
25VT-CK10
SERVICE ADJUSTMENT
VCO Adjustment
1. Connect a digital voltmeter between pin(44) of IC401
and ground.
2. Select a good local channel.
3. Enter the service mode. select adjustment “PIFVCO” and data value “64”.
4. Adjust the VCO coil T201 so that the digital voltmeter
reads 2.5 volts.
5. Adjustment is complete, remove the voltmeter,
return to “normal” mode.
RF AGC Adjustment
1. Have unit receive a good local channel.
2. Enter the service mode and select service
adjustment “RF-AGC”.
3. Set the data value to point where no noise or beat
appears.
4. Select another channel to confirm that no noise or
beat appears.
Note 1: You will have to come out of the service
mode to select another channel.
Note 2: Setting the data to “0” will produce a
black raster.
Screen adjustment
1. Select a good local channel.
2. Enter the service mode and select service
adjustment “COLOR” and set the data value to “0”
to set the color level to minimum.You may skip this
step if you selected a B/W picture or monoscope
pattern.
3. Select service adjustment “MUTE” and adjust the
data value to “1” this turns off the luminance signal
(Y-mute) .
4. Select service adjustment “BRIGHT” and adjust data
value to "28".
5. Adjust the master screen control untill raster darkens
to the point where raster is barely seen.
6. Adjust service adjustments “R-CUT OFF” red,”GCUT OFF" green and “B-CUT OFF” blue to obtain
a good grey scale with normal whites at low
brightness level.
7. Select service adjustment “MUTE” and reset data
to” 0" Select service adjustment “COLOR” and reset
data to obtain normal color level.
8. Remove digital voltmeter. reset master screen
control to obtain normal brightness range.
White balance adjustment
1. Have unit receive a good local channel.
2. Enter the service mode. select service adjustment
“COLOR” and set to “0” ( minimum color) . “COLOR”
does not have to be adjusted if you selected a B/W
picture or monoscope pattern.
3. Alternately adjust service adjustment data of “G
GAIN” and “B GAIN” untill a good grey scale with
normal whites is obtained.
4. Select service adjustment “COLOR”and adjust data
to obtain normal color level.
Sub-picture adjustment
1. Have unit receive a good local channel.
2. Make sure the customer picture control is set to
maximum.
3. Enter the service mode and select service
adjustment “PICTURE”.
4. Adjust the data value to achieve normal contrast
range.
Sub-Tint Adjustment
1. Have unit receive a good local channel.
2. Set customer tint control to center of it’s range.
3. Enter the service mode and select service
adjustment “TINT”.
4. Adjust “TINT” data value to obtain normal flesh tones.
Sub-color adjustment
1. Have unit receive a good local channel.
2. Make sure the customer color control is set to
center position .
3. Enter the service mode and select service
adjustment “COLOR”.
4. Adjust “COLOR”data value to obtain normal color
level.
Sub-brightness adjustment
1. Have unit receive a good local channel.
2. Make sure the customer brightness control is set to
center position.
3. Enter the service mode and select service
adjustment “BRIGHT”.
4. Adjust “BRIGHT”data value to obtain normal
brightness level.
15
25VT-K100
25VT-CK10
Vertical-size adjustment
1. Have unit receive a good local channel.
2. Enter the service mode and select service
adjustment “V-AMP”.
3. While observing the top and bottom of the screen,
adjust “V-AMP” data value to proper vertical size and
linearity.
Horizontal position adjustment
1. Have unit receive a good local channel.
2. Enter the service mode and select service adjustment
“H-PHASE”.
3. Adjust “H-PHASE” data value so that picture is
centered.
Caption position adjustment (horizontal)
1. Have unit receive a good local channel.
2. Enter the service mode and select service adjustment
“TEXT POSITION”.
3. A black text box appears on the screen (see
Figure B.) .
4. Adjust “TEXT POSITION” data value so that text box
is positioned in the center of the screen.
Figure B.
16
TROUBLESHOOTING OF TV SECTION
25VT-K100
25VT-CK10
FLOW CHART NO.2-2
Blown out
NO RASTER
F701 Check
Replace the Fuse
Normal
The Fuse is again
blown out
T701 Pin (7) voltage
check about: 170V DC
at 120V AC
Abnormal
IC701, Check
Normal
R701
Normal
D701, D702, D703,
D704, D705
side)
±
Normal
voltage check about:
+
B
128.5V (C730
Abnormal
IC701, D727
Abnomal
IC401 (iX2933CE)
Normal
CRT connector
GC1~GC5 bias check
Normal
R603, Q601,
Q612
C854
FLOW CHART NO.2-1
Connect AC cord.
NO
Set not operating
Is AC cord connected?
AC cord broken.
NO
YES
Is 120V AC applied to
YES
line between (H) and
(C) of P702 ?
Is 170V DC applied to
NO
Check R708 and
IC701.
NO
YES
C705?
Is 16V DC applied to
pin (4) of IC701 ?
Check D701 thru
D704, L701,
Check IC701 and
adjacent parts
NO
YES
Does pulse waveform
R701 and F701.
YES
exist at line between (2)
and (3) of IC701 ?
17
Check T701, and
adjacent parts.
25VT-K100
25VT-CK10
Abnormal
FLOW CHART NO.2-4
Vertical freq check
CF631 (503kHz)Normal
NO VERTICAL SCAN
Abnormal
IC401 pin (22) bias
IC401
Normal
check.
Abnormal
R511, D502, C509,
C510
Normal
IC501 (TA8403) bias
check.
Check the CRT
connector K1~K5 and
adjacent parts.
FLOW CHART NO.2-3
NO SoundNO Picture
Picture noise
decrease but sound
level varies greatly.
NO PICTURE, NO SOUND
Does the noise level increase at max,
Contrast, Brightness, and Sound Control ?
NO
NO
Is there
a signal
Check
the
IC401
Is there a signal at
pin (53) of IC401 ?
YES
NO
Is there a signal at
pin (37) of IC401 ?
NO
NO
Is there
a signal
at pin
Check the IC401 and adjacent parts
YESYES
at pin
(54) of
IC401 ?
and
adjacen
t parts.
YESYES
(8) & of
IC351
(TDA
7233) ?
Check the Q431
and adjacent parts.
NO
YES
Check
the
Check
NO
Is there
a signal
IC401,
and
adjacent
the
IC351.
at pin
(5) of
parts.
IC351 ?
YES
Check
the
speaker.
Does the 9V (+B)
appear at pin (48)
of the IC401 ?
Abnormal
Check IC2001.
Normal
Abnormal
Normal
Abnormal
Check the
PC9V line.
Check the
IC401.
Check the
IC401.
noise increases but no
Circuit to be checked:
1. TUNER
2. PIF
3. Automatic gain control
4. 9V power source
signal is received
Is there a signal at pin
(41) of IC401 ?
Is there a signal at pin
(43) of IC401 ?
18
Check the tuner bias.
Check the IC401 and
adjacent parts.
Check the Tuner AGC.
Normal
Check the
Tuner circuit.
Check the VCR:
TROUBLESHOOTI
FLOW CHART NO.2-7
NG "NO SOUND".
25VT-K100
25VT-CK10
FLOW CHART NO.2-8
NO
YES
Is there a signal at pin
(55) of IC401 ?
Check the TV:
TROUBLESHOOTING
"NO SOUND".
NO PLAYBACK SOUND
Check the 5V and GND lines.
Replace the infrared remote control
as required.
NO
INFRARED R/C TROUBLESHOOTING
No operation is possible from the
infrared remote control.
Does the infrared remote control
NO
YES
function ?
YES
Is 5V applied at pin (2) of the
remote control receiver ?
Reposition the set not to be
Check pin (10) of IC2001 and /or
receiver.
NO
Is "L" pulse given out of pin (1) of
the receiver and received at pin (4)
of IC2001, when the infrared remote
NO
YES
Is fluorescent lighting enough away
control is activated ?
Check key input terminals.
exposed to strong light.
NO
YES
from the set ?
YES
Is there short-circuit in the key input
or IC2001 ?
Check IC2001
FLOW CHART NO.2-5
Check IC401, and
adjacent parts.
NO
YES
YES
NO SOUND
Does waveform appear
Does waveform appear
at pin (54) of IC401 ?
NO
at pin (8) of IC351 ?
Check IC401 and
adjacent parts
YES
Check IC351 and
adjacent parts.
Does approx. 11V appear
at pin (3) of IC351 ?
NO
Check D725, R327,
C725, C726, FB726
FLOW CHART NO.2-6
Check the VCR:
TROUBLESHOOTI
NG "NO
PLAYBACK".
NO
YES
Check IC401 and
adjacent parts as same
Is there a signal at pin
(39) of IC401 ?
as "NO PICTURE".
NO PLAYBACK PICTURE
19
25VT-K100
PWB-E
POWER
SW UNIT
PWB-D
VCR KEY UNIT
25VT-CK10
CHASSIS LAYOUT
H
G
F
PWB-B
CRT UNIT
E
PWB-F
SENSOR
D
UNIT
PWB-C
C
SUB POWER
UNIT (25VT-CJ100. ONLY)
B
A
123456
20
MODEL:25VT-K100
PWB-A
H
MAIN UNIT
G
F
25VT-K100
25VT-CK10
E
D
C
B
A
123456
21
25VT-K100
25VT-CK10
MODEL:25VT-CK10
PWB-A
H
MAIN UNIT
G
F
E
D
C
B
A
123456
22
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
23
24
MODEL 25VT-K100 BLOCK DIAGRAM OF TV SECTION
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
MODEL 25VT-CK10 BLOCK DIAGRAM OF TV SECTION
25
26
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
27
28
MODEL 25VT-K100 OVERALL SCHEMATIC DIAGRAM
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
2930
MODEL 25VT-CK10 OVERALL SCHEMATIC DIAGRAM
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
31
32
H
G
F
E
D
C
B
A
123456
SCHEMA TIC DIA GRAM :
CRT , SUB POWER Unit
NOTES:
1. The unit of resistance "ohm" is omitted
(K:1000 ohms, M:1 Meg ohm).
2. All resistors are 1/8 watt, unless otherwise noted.
3. All capacitors are µF , unless otherwise noted P: µµF.
4. (G) indicates ±2% tolerance may be used.
VOLTAGE MEASUREMENT CONDITIONS:
1. All DC voltages are measured with DVM connected
between points indicated and chassis ground, line
voltage set at 120V AC and all controls set for normal
picture unless otherwise indicated.
2. All voltages measured with 1000µV B&W or Color
signal.
DESCRIPTION OF SCHEMATIC DIAGRAM
å
AND SHADED ( ) COMPONENTS
= SAFETY RELATED PARTS.
ç
MARK= X-RAY RELATED PARTS.
DRGANNES MARQUES-ET HACHRES ( ):
PIECES RELATIVES A LA SECURITE.
MARQUE
ç
: PIECS RELATIVE AUX RAYONS X.
This circuit diagram is a standard one, printed
circuits may be subject to change for product
improvement without prior notice.
WAVEFORM MEASUREMENT CONDITIONS:
1. Photographs taken on a standard gated color bar
signal, the tint setting adjusted for proper color. The
wave shapes at the red, green and blue cathodes of
the picture tube depend on the tint, color level and
picture control.
2.indicates waveform check points (See chart,
waveforms are measured from point indicated to
chassis ground.)
WAVE FORMS
SUB POWER(25VT-CK10. ONLY)
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
3334
MODEL 25VT-K100 SCHEMATIC DIAGRAM : MAIN Unit (TV Section)
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
35
36
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
3738
MODEL 25VT-CK10 SCHEMATIC DIAGRAM : MAIN Unit (TV Section)
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
40
39
H
G
F
E
D
C
B
A
123456789101112
25VT-K100
25VT-CK10
25VT-K100
25VT-CK10
4142
SCHEMATIC DIAGRAM : MAIN, SENSOR Unit (VCR Section)
SAFETYNOTE:Componentsmarkedwitha(å ) have special
characteristi cs important t o safety. Before replaccing any of these
components, read carefully the SAFETY NOTICE on page 3 of the
Service Man ual. Com ponents mar ked wi th an ( ç ) are r elated t o X-
Ray Protection circuit .
Les pi`eces de rechange qui pr élelesentent ces caract éleristiques sp
éleciales de s élecurit éle, sont identifi élees dans ce manuel : les pi`eces
élelectriques qui pr élesentent ces particularit éles, sont rep éler élee
par la marque å et sont hachur élees dans les listes de pi`eces et dans
les diagrammes sch élematiques.
La substitution d'une pi`ece de rechange par une autre qui ne pr éLesente
pas les m éoemes caract éLeristiques de s élecurit éle que la pi`ece
recommand élee parl'usine et dans ce manuel de service, peut provoquer
une éLelectrocution, un incendie ou toutautre sinistre.
"HO W TO ORDER REPLA CEMENT PART S"
CHANGE DES PIECES
To have your order filled promptly and correctly, please furnish the
following informations.
1. MODEL NUMBER 2. PAR T NO.
3.PRICE CODE 4 . DESCRIPTION
Contact your nearest SHAR P Parts Distributor to order .
For locat ion of SH AR P Part s Di stri butor , Plea se call Toll-Free; 1- 800BE-SHARP
1LBNDK1009AJZZV Tension Band Ass’yAH
2LBOSZ1001AJZZV T ension Arm bossAB
3LBOSZ1002AJZZV Slow Brake BossAD
4LBOSZ1003AJZZV Cassette Stay LAC
5LCHSM0158AJZZV Main Chassis Ass’yBA
6LHLDZ1958AJZZV Loading Motor BlockAG
7LPOLM0056GEZZV Supply Pole Base Ass’yAM
8LPOLM0057GEZZV Take Up Pole Base Ass’yAM
9MLEVF0459AJZZV Take-Up Loading ArmAF
Ass’y
10MLEVF0461AJZZV Supply Loading ArmAF
Ass’y
11MLEVF0463AJZZV Pinch Drive Lever Ass’yAG
12MLEVF0464GEZZV Pinch Roller LeverAW
Ass’y
15MLEVF0467AJZZV Tension Arm Ass’yAK
16MLEVF0468AJFW V Audio/Control Head ArmAG
17MLEVP0271AJZZV Sifter Drive LeverAE
18MLEVP0272AJZZV Pinch Double ActionAD
Lever
19MLEVP0273AJZZV Reverse Guide LeverAL
Ass’y
20MLEVP0275AJZZV Reverse Drive LeverAD
21MLEVP0276AJZZV Slow BrakeAE
22MLEVP0277AJZZV Open LeverAD
23MLEVP0278AJZZV Clutch LeverAE
24MLEVP0288AJZZV Sup Main Brake Ass’yAF
25MLEVP0289AJZZV Take-Up Main BrakeAF
Ass’y
26CLEVP0287AJZZV Auto Head Cleaner Ass’yAG
27MSLiP0008AJZZV SifterAH
28MSPRC0205AJFJV Audio/Control HeadAC
Spring
29MSPRD0175AJFJV Reverse Guide SpringAE
30MSPRT0402AJFJV Loading Double ActionAE
49NROLP0110GEZZJ Guide RollerAH
50NSFTP0034AJZZJ Tension Pole AdjusterAB
51PGUMM0043AJZZ V Damper RaberAD
52PREFL1007AJZZV Light GuideAE
53QCNW-0247AJZZV FFC for Drum MotorAG
54QCNW-0271AJZZV Lead Wire for LoadingAD
Motor
55QCNW-0272AJZZV FFC for Audio/ControlAF
56QPWBF5243AJZZ V Audio/Control Head PWBAE
57QSOCN0605REN1 J Socket, 6 pinAB
58RHEDT0031AJZZJ Full Erase HeadAX
59RHEDU0085GEZZ J Audio/Control HeadBA
60RMOTM1062GEZZ V Loading MotorAP
61RMOTN2053GEZZ V Capstan MotorBF
62RMOTP1129GEZZ V Drum Drive MotorBF
63DDRMW0014TEX0 V Upper and lower drumBQ