Sony Trinitron KV-21FT250 User manual

TRINITRON®COLOR TELEVISION
SERVICE MANUAL BX-1S CHASSIS
MODEL NAME REMOTE COMMANDER DESTINATION CHASSIS NO.
9-883-762-02
KV-21FT250 RM-YA005 LATIN NORTH SCC-S85A-A
HISTORY INFORMATION FOR THE FOLLOWING MANUAL:
ORIGINAL MANUAL ISSUE DATE: 8/2007
☛
:UPDATED ITEM
REVISION DATE SUBJECT
8/2007 No revisions or updates are applicable at this time.
5/2008 Added new PN for IC IC001. New PN includes software data. Replaced pg. 60.

TRINITRON®COLOR TELEVISION
SERVICE MANUAL BX-1S CHASSIS
MODEL NAME REMOTE COMMANDER DESTINATION CHASSIS NO.
9-883-762-02
KV-21FT250 RM-YA005 LATIN NORTH SCC-S85A-A
Self Diagnosis
Supported model
KV-21FT250 RM-YA005

KV-21FT250
KV-21FT250
3
TABLE OF CONTENTS
Specifications ................................................................................. 4
Warnings and Cautions .................................................................. 5
Safety Check-Out ........................................................................... 6
Self-Diagnostic Function................................................................. 7
SECTION 1: DISASSEMBLY................................................................. 9
1-1. Rear Cover Removal.............................................................. 9
1-2. Speaker and Tweeter Removal.............................................. 9
1-3. Chassis Assembly Removal................................................. 10
1-4. Service Position ................................................................... 10
1-5. Picture Tube Removal...........................................................11
Anode Cap Removal Procedure ...........................................11
SECTION 2: WIRE DRESSING ........................................................... 12
2-1. H3 Board Caution Point ....................................................... 12
2-2. A Board UL Wire Dressing ................................................... 12
2-3. Connector Assembly Caution............................................... 12
2-4. C Board ................................................................................ 13
2-5. A Board ................................................................................ 13
2-6. A Board (Continued)............................................................. 14
2-7. AC Power Cord and Speakers ............................................. 15
2-8. AC Power Cord and Speakers (Continued)...................... 16
2-9. DY Wire Dressing................................................................. 17
2-10.FBT Wire Dressing............................................................... 18
2-11. HV Cap Assembly ................................................................ 19
2-12.AC Power Cord to Rear Cover............................................. 19
SECTION 3: SET-UP ADJUSTMENTS................................................ 20
3-1. Beam Landing Adjustment ................................................... 20
3-2. Convergence Adjustment ..................................................... 21
3-3. Focus Adjustment................................................................. 22
3-4. G2 (Screen) Adjustment....................................................... 23
SECTION 4: CIRCUIT ADJUSTMENTS.............................................. 24
4-1. Remote Adjustment Buttons and Indicators......................... 24
4-2. Accessing the Service Menu Mode...................................... 25
4-3. Confirming Service Adjustment Changes............................. 26
4-4. White Balance Adjustments ................................................. 26
4-5. Picture Quality Adjustments ................................................. 26
4-6. Service Data......................................................................... 28
SECTION 5: DIAGRAMS..................................................................... 43
5-1. Circuit Boards Location ........................................................ 43
5-2. Printed Wiring Board and Schematic Diagram Information.. 43
5-3. Block Diagram...................................................................... 44
5-4. Schematics and Supporting Information .............................. 45
A Board Schematic Diagram (1 of 6).................................... 45
A Board Schematic Diagram (2 of 6).................................... 46
A Board Schematic Diagram (3 of 6).................................... 47
A Board Schematic Diagram (4 of 6).................................... 48
A Board Schematic Diagram (5 of 6).................................... 49
A Board Schematic Diagram (6 of 6).................................... 50
C Board Schematic Diagram................................................ 52
H3 Board Schematic Diagram.............................................. 53
5-5. Semiconductors ................................................................... 54
SECTION 6: EXPLODED VIEWS ........................................................ 55
6-1. Chassis, Picture Tube and Speakers ................................... 55
SECTION 7: ELECTRICAL PARTS LIST............................................ 56
SECTION TITLE PAGE SECTION TITLE PAGE

KV-21FT250
KV-21FT250
4
SPECIFICATIONS
Television system
NTSC, PAL-M/PAL-N
Channel coverage
VHF: 2-13/UHF: 14-69/CATV: 1-125
Picture tube
FD Trinitron®tube
Visible screen size
508.5 mm (20-inch) picture measured diagonally
Actual screen size
545 mm (21-inch) measured diagonally
Supplied Accessories
Remote Commander RM-YA005
Two Size AA (R6) Batteries
1) 1 Vp-p 75 ohms unbalanced, sync negative
2) 500 m Vrms (100% modulation), Impedance: 47 kilohms
3) This specification is the maximum wattage.
Design and specifications are subject to change without notice.
Trademarks and Copyrights
Sony, FD Trinitron, WEGA
®
, Steady Sound and Intelligent Picture
are
registered trademarks of Sony Corporation.
As an ENERGY STAR® Partner, Sony
Corporation has determined that this
product meets the ENERGY STAR®
guidelines for energy efficiency. ENERGY
STAR® is a U.S. registered mark.
KV-21FT250
Power Requirements
Number of Inputs/Outputs
Video 1) 3
Audio 2) 4
Component Video 1
Headphone Video 1
S
p
eaker Out
p
ut
(
W
)
5W + 5W
Power Consumption (W)
In Use (Max) 108W
In Standby (Max) 3) <1W
Dimensions (W x H x D)
mm 638 x 458 x 482 mm
Mass
kg 25 kg
120V AC, 50/60Hz

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5
WARNINGS AND CAUTIONS
CAUTION
Short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT shield, or carbon painted on the CRT, after
removing the anode.
WARNING!!
An isolation transformer should be used during any service to avoid possible shock hazard, because of live chassis. The chassis of this
receiver is directly connected to the AC power line.
!SAFETY-RELATED COMPONENT WARNING!!
Components identified by shading and ! mark on the schematic diagrams, exploded views, and in the parts list are critical for safe
operation. Replace these components with Sony parts whose part numbers appear as shown in this manual or in supplements published
by Sony. Circuit adjustments that are critical for safe operation are identified in this manual. Follow these procedures whenever critical
components are replaced or improper operation is suspected.

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KV-21FT250
6
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered
connections. Check the entire board surface for solder splashes and
bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that
you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the B+ and HV to see if they are specified values. Make sure
your instruments are accurate; be suspicious of your HV meter if
sets always have low HV.
8. Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described below.
Leakage Test
The AC leakage from any exposed metal part to earth ground and from
all exposed metal parts to any exposed metal part having a return to
chassis, must not exceed 0.5 mA (500 microamperes). Leakage current
can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instructions.
2. A battery-operated AC milliampmeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The “limit” indication is 0.75 V,
so analog meters must have an accurate low voltage scale. The
Simpson’s 250 and Sanwa SH-63TRD are examples of passive
VOMs that are suitable. Nearly all battery-operated digital
multimeters that have a 2 VAC range are suitable (see Figure A).
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate
retaining screw on most AC outlet boxes is also at earth ground. If the
retaining screw is to be used as your earth ground, verify that it is at
ground by measuring the resistance between it and a cold-water pipe
with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble-
light (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on
the line; the lamp should light at normal brilliance if the screw is at
ground potential (see Figure B).
To Exposed Metal
Parts on Set
0.15 μF 1.5 K ΩAC
Voltmeter
(0.75 V)
Earth Ground
Trouble Light
AC Outlet Box Ohmmeter
Cold-water Pipe
Figure A. Using an AC voltmeter to check AC leakage. Figure B. Checking for earth ground.

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7
Detected Symptoms
SELF-DIAGNOSTIC FUNCTION
*One flash count is not used for self-diagnostic.
*If a +B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously. The symptom that is diagnosed first by the mircrocontroller
is displayed on the screen.
**Refer to Screen (G2) Adjustments in Section 2-4. of this manual.
2. Display of STANDBY LED Flash Count
2 times
4 times
5 times
LED ON 0.3 sec.
LED OFF 0.3 sec. LED OFF
3 sec.
Standby indicator
3. Stopping the STANDBY LED Indicator Flash
Turn off the power switch on the TV main unit or unplug the power cord from the outlet to stop the STANDBY LED Indicator from flashing.
4. Self-Diagnostic Screen Display
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past
occurrences of failure on the screen for confirmation.
Self Diagnosis
Supported model
The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY LED indicator will automatically begin to flash. The number of
times the LED flashes translates to a probable source of the problem. A definition of the STANDBY LED flash indicators is listed in the instruction manual
for the user’s knowledge and reference. If an error symptom cannot be reproduced, the Remote Commander can be used to review the failure occurrence
data stored in memory to reveal past problems and how often these problems occur.
1. Diagnostic Test Indicators
When an error occurs, the STANDBY LED indicator will flash a set number of times to indicate the possible cause of the problem. If there is more than
one error, the indicator will identify the first of the problem areas.
Results for all of the following diagnostic items are displayed on screen. No error has occurred if the screen displays a “0”.
Power does not turn on
+B overcurrent (OCP)*
V-Protect (OVP)
IK (AKB)
Does not light
2 times *
4 times
5 times
2:0
or
2:1 - 255
4:0
or
4:1 - 255
5:0
or
5:1 - 255
• Power cord is not plugged in.
• Fuse is burned out (F600). (A Board)
• H.OUT (Q805) is shorted. (A Board)
• IC751 is shorted. (C Board)
• +13V is not supplied. (A Board)
• IC804 is faulty. (A Board)
• Video OUT (IC1545) is faulty(A Board)
• IC001 is faulty. (A Board)
• Screen (G2) is improperly adjusted.**
No. of Times
STANDBY LED
Indicator Flashes
Diagnostic Item
Description
Self-Diagnositc
Display/
Diagnostic Result
Probable Cause Location
• Power does not come on.
• No power is supplied to the TV.
• AC Power supply is faulty.
• Power does not come on.
• Load on power line is shorted.
• Has entered standby state after horizontal raster.
• Vertical deflection pulse is stopped.
• Power line is shorted or power supply is stopped.
• No raster is generated.
• CRT Cathode current detection reference pulse
output is small.
Power Supply
NG (+5V) for
Video Processor
8 times 8:0
or
8:1 - 255
• IC604 is faulty.
• IC602 is faulty.
• No power supply to CRT Anode.
• No RASTER is generated.

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8
To Bring Up Screen Test
In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:
DISPLAY Channel 5 Sound Volume -
POWER
Note that this differs from entering the Service Mode (Sound Volume +).
The following screen will be displayed indicating the error count:
SELF DIAGNOSTIC
2 OCP : 0
3 OVP : N/A
4 VSTOP : 0
Number “0” means that no fault was detected.
5 AKB : 1 Number “1” means a fault was detected one time only.
8 SUP : 0
101 WDT : N/A
N/A meanus not available for this model.
Handling of Self-Diagnostic Screen Display
Since the diagnostic results displayed on the screen are not automatically cleared, always check the self-diagnostic screen during repairs. When you
have completed the repairs, clear the result display to “0”.
Unless the result display is cleared to “0”, the self-diagnostic function will not be able to detect subsequent faults after completion of the repairs.
Clearing the Result Display
To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:
Channel 8
0
Quitting the Self-Diagnostic Screen
To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.
Self-Diagnostic Circuit
A BOARD
IC001
Y/CHROMA JUNGLE
A BOARD
IC804
V. OUT
A BOARD
IC001
SYSTEM
A BOARD
IC003
MEMORY
IK
FROM
C BOARD
IC751 PIN 5
EHTO
FROM
A BOARD
Q816
COLLECTOR
32 RED-LED
F.B-PLS
V. GUARD
SDAO
SDA
DISPLAY
84 313
122
5
109
+B overcurrent (OCP)
Occurs when an overcurrent on the +B (135V) line is detected by pin 32 of IC001 (A Board). If the voltage of pin 32 of IC001 (A Board) is more than 4V
when V.SYNC is more than seven verticals in a period, the unit will automatically turn off.
V-Protect
Occurs when an absence of the vertical deflection pulse is detected by pin 13 of IC001 (A Board). Power supply will shut down when waveform interval
exceeds 2 seconds.
IK (AKB)
If the RGB levels* do not balance within 15 seconds after the power is turned on, this error will be detected by IC001 (A Board). TV will stay on, but there
will be no picture.
Power Supply NG (+5V) for Video Processor
Occurs when IC001 internal HV protect detects an abnormal H-Pulse (frequency) due to improper power supply to IC001. The TV cuts off high voltage
power of anode CRT. No picture will be detected. eg: faulty IC602 or IC604

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9
1-1. REAR COVER REMOVAL
SECTION 1: DISASSEMBLY
1-2. SPEAKER AND TWEETER REMOVAL
1
Remove 8 screws from Rear Cover.
(+BVTP 4 X 16 TYPE2 IT-3)
2
Remove 1 screw from terminal bracket on Rear Cover.
(+BVTP 4 X 16 TYPE2 IT-3)
3
Slide to remove Rear Cover from Beznet.
1
Remove 2 screws from Tweeter.
(+BVTP 3 X 12 TYPE2 TT (B))
2
Remove 2 screws from Speaker.
(+PWTP2 4 X 16)
9 screws
Rear cover
1
1 screw
2
3
1
2

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10
1-4. SERVICE POSITION
1
Rotate A Board.
1
2
1
4
3
5
1
Remove AC cord from holder on bottom cover.
2
Disconnect H3 Board connector from CN005 on the A Board.
3
Release claw and slide out A Board.
4
Disconnect speaker wire from CN200 on the A Board.
5
Slide to move A Board
1-3. CHASSIS ASSEMBLY REMOVAL

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11
1-5. PICTURE TUBE REMOVAL
WARNING: BEFORE REMOVING THE ANODE CAP
High voltage remains in the CRT even after the power is disconnected. To avoid electric shock,
discharge CRT before attempting to remove the anode cap. Short between anode and CRT
coated earth ground strap.
ANODE CAP REMOVAL PROCEDURE
WARNING: High voltage remains in the CRT even after the power is disconnected. To avoid electric shock, discharge CRT before attempting to remove
the anode cap. Short between anode and coated earth ground strap of CRT.
NOTE: After removing the anode cap, short circuit the anode of the picture tube and the anode cap to either the metal chassis, CRT shield, or carbon
painted on the CRT.
REMOVAL PROCEDURES
HOW TO HANDLE AN ANODE CAP
1. Do not use sharp objects which may cause damage to the surface of the
anode cap.
2. To avoid damaging the anode cap, do not squeeze the rubber covering too
hard. A material fitting called a shatter-hook terminal is built into the rubber.
3. Do not force turn the foot of the rubber cover. This may cause the shatter-
hook terminal to protrude and damage the rubber.
Turn up one side of the rubber cap in
the direction indicated by arrow a.
Use your thumb to pull the rubber
cap firmly in the direction indicated
by arrow b.
When one side of the rubber cap separates from
the anode button, the anode cap can be removed
by turning the rubber cap and pulling it in the
direction of arrow c.
a
b
Anode Button
c
5
6
3
2
4
1
10
8
9
7
1
Discharge the anode of the CRT and remove the
anode cap.
2
Unplug all interconnecting leads from the deflection
yoke, neck assembly, degaussing coils and CRT
grounding strap.
3
Remove the C Board from the CRT.
4
Remove the chassis assembly.
5
Loosen the neck assembly fixing screw and
remove.
6
Loosen the deflection yoke fixing screw and
remove.
7
Place the set with the CRT face down on a cushion
and remove the degaussing coil holders.
8
Remove the degaussing coils.
9
Remove the CRT grounding strap and spring
tension devices.
10
Unscrew the four CRT fixing screws [located on
each CRT corner] and remove the CRT.
[Take care not to handle the CRT by the neck tube.]

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12
2-1. H3 BOARD CAUTION POINT
SECTION 2: WIRE DRESSING
Connector Assy,
3P P/N: 1-910-031-76
Refer to
printing:
GRAY wire to
Pin 3 (KEY)
Refer to
printing:
WHITE wire
to
Pi 1 (GND)
CAUTION:
Make sure Connector Assy,
3P (P/N: 1-910-031-76) is
inserted to correct pins:
--> WHITE wire to Pin 1
--> GRAY wire to Pin 3
--> Pin 2 is NOT connected
CAUTION:
Prevent tie, cable from
touching rear cover or any
enclosures by turning them
away from it
--> avoid rattle sound. Also
prevent tie, cable's end from
touching solder side of
board.
R82
R829
R889
W068
W069
UL wire
P/N 1-923-082-52
CAUTION:
Prevent tie, cable from touching
rear cover or any enclosures by
turning them away from it
--> avoid rattle sound. Also
prevent tie, cable's end from
touching solder side of board.
Dress UL Wire (1-923-082-52) according to Figure 1(b) as
shown
Note : Ensure UL wire does not touch high temperature
resistors R828, R829 & R889
Ensure UL wire does not touch high
temperature resistors R828, R829 & R889
C/M for picture bending
due to introduction of
Sparkling Wega 2 Features
(DCN : S0062)
CAUTION:
Dress & control mounted wires on C boards
if necessary :
--> ensure wires do not get trapped during
solder dip process
--> ensure wires do not get punched by ICT
jig. (modify ICT jig if applicable)
2-2. A BOARD UL WIRE DRESSING
2-3. CONNECTOR ASSEMBLY CAUTION

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KV-21FT250
13
g
Dress Conn Assy, 7P (RGB) with
Cable Tie at alignment hole, A as shown.
Make sure Conn Assy, 7P (RGB)
does not direct contact with heat
sink of IC751
Conn Assy, 7P
(RGB)
Cable Tie, A
CAUTION:
Prevent tie, cable from touching
rear cover or any enclosures by
turning them away from it
--> avoid rattle sound. Also
prevent tie, cable's end from
touching solder side of board.
Lead Assy, Focus
FBT Flange
Make sure rubber cap is pushed
down to make sure it covers
the FBT flange completely
HV Cap Assy
FBT Flange
TVSR Requirement :
All Connectors must be kept away from FBT area by a minimum distance of
10mm
R121
)
OK
NG
Make sure Conn Assy, 5P
does not touch resistor, R121
Lead Assy, Jumper
Conn Assy, 5P (YUV)
Pin, Wire A021 Figure 5
Figure 5(a) Figure 5(b)
Shield case
Shield case
C/M for OSD drift from RF to no signal
Make sure the Connector Assy, 5P
(YUV) is press down towards the
board
1) Dress Conn Assy, 5P (YUV) & Lead Assy, Jumper with Pin, Wire A021 as shown.
2) Dress Lead Assy, Jumper according to the route shown in the Figure..
Note : Ensure Lead Assy, Jumper is dress away from shield case in the boxed area in Figure 5.
Ensure Lead Assy, Jumper is dress below Conn Assy, 5P (YUV).
Make sure the UL tape is positioned
at the sharp edge of shield case to
prevent wire from being scratched
Conn Assy, 5P (YUV)
Lead Assy,
CAUTION:
1) Dress Lead Assy, Jumper according to the route shown
in the Figure 5.
=> Ensure Lead Assy, Jumper is dress away from shield
case in the boxed area.
=> Ensure Lead Assy, Jumper is dress below Conn Assy,
5P (YUV).
2-4. C BOARD
2-5. A BOARD

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14
A B C
A
B C
DY
90
Note : Keep Lead Assy, Earth away from heat sinks.
Note : Keep Lead Assy, Earth away from heat sinks.
Rotation
al Coil
Conn Assy, 7P
Keep Lead Assy, Earth away from heat
Purse Lock Ø5 Lead Assy, Earth
Keep Lead Assy, Earth away from heat
Lead Assy, Earth
Conn Assy, 7P
Purse Lock Ø5
UL Wire (1-923-000-81)
Purse Lock Ø5
Purse Lock Rotation CoilRotation Coil
A: Conn Assy, 7P
B: Lead Assy, Earth
C: UL Wire (1-923-000-81)
D: Rotational Coil Conn
A: Conn Assy, 7P
B: Lead Assy, Earth
C: UL Wire (1-923-000-81)
Non-Rotational Coil Models
Rotational Coil
Dress Conn Assy, 7P, UL Wire (1-923-000-81) and Lead Assy,
with purse lock, Ø5 as shown.
Dress Conn Assy, 7P, UL Wire (1-923-000-81), Lead Assy,
Earth and Rotational Coil Conn with purse lock, Ø5 as shown.
Non-Rotational Coil Models Rotational Coil Models
CAUTION:
Do not overpull the wires during
dressing --> avoid disconnection
of wires.
UL Wire (1-923-000-81)
Wire from
Rotation coil
2-6. A BOARD (CONTINUED)

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15
1) Dress AC Power Cord, Lead Assy, Earth and Lead Assy, Speaker (Right) inside standing purse lock.
Note : Do not lock the standing purse lock. (will be lock after putting in DGC Conn in Overall Assy)
Keep bunch of wires above of RY600 to avoid wires from being sandwiched with front jack and pushed against relay.
2) Dress AC Power Cord and Lead Assy, Speaker (Left) with Pin, Wire A016 as shown.
Note : Dress AC Power Cord & Lead Assy, Speaker (Left) above the surrounding capacitors to prevent from touching high-temp parts.
Lead Assy,
Lead Assy, Speaker
Figure 6(a)
AC Cord Holder
540 ± 5 mm
Heat Sink, A004
Dress AC Power Cord & Lead Assy,
Speaker (Left) above the surrounding
capacitors to prevent from touching high-
temp parte.
AC Power
RY600
Standing Lead Assy, Speaker
Pin, Wire
2-7. AC POWER CORD AND SPEAKERS
yyp(g) g
Dress DGC Conn into standing purse lock and lock the standing purse lock.
Note : 1) AC Power Cord, Lead Assy, Earth and Lead Assy, Speaker (Right) already inserted into standing purse lock during Chassis Assy.
2) Keep bunch of wires above of RY600 to avoid wires from being sandwiched with front jack and pushed against relay.
3) Dress wires away from beznet's front terminal to prevent wires from being sandwiched when docking.
4) Dress speaker wires above the surrounding capacitors to prevent from touching high-temp parts.
Dress wires away from beznet's front terminal
--> prevent wires from being sandwiched when docking chassis.
Lead Assy, Speaker (Right)
AC Power Cord
Lead Assy, Earth
Keep bunch of wires above of RY600
--> to avoid wires from being sandwiched with
front jack and pushed against relay
DGC Conn
RY600
Standing Purse Lock
Pin, Wire A016 AC Power Cord
Lead Assy, Speaker
DGC
Lead Assy,
AC Power
Standing Purse
Lock
Lead Assy, Speaker (Left)
Wire dressing done during chassis
half way docked into beznet.
Dress speaker wires above the surrounding capacitors
--> prevent from touching high-temp parts.

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16
Tweeter's
Tab
Spring
extension
Black Tape
Ensure DGC
Conn is kept
behind of DGC
Ensure DGC conn is in front
of DGC before dress with
standing purse lock.
Standing
purse lock
iii) Dress DGC conn according to Figure.
Note : Kept DGC conn close to the CRT.
Ensure all wires is keep away from heatsinks
or other high temperature parts.
Make sure wire does not
touch heatsink or other
high temperature parts.
Lead Assy, Speaker is
dress underneath DGC.
(Sandwiched between
DGC & CRT surface.)
Ensure tweeter's tab is
facing inisde (towards
CRT) to avoid wire
being sandwich while
docking rear cover.
i) Ensure Tweeter's tab is facing inside (towards CRT).ii) Dress Lead Assy, Speaker (Right) underneath DGC.
Note : Avoid wire being sandwich while docking rear (Sandwiched between DGC & CRT surface)
CAUTION:
Keep wires away from sharp edge of spring
extension
Ensure DGC
Conn is kept
behind of black
tape.
2-8. AC POWER CORD AND SPEAKERS (CONTINUED)
yp ( ) g
1) Insert Lead Assy, Speaker (Left) followed by AC Power Cord into CRT support's hook.
Note : Ensure wires do not come out from hook.
Keep wires away from heat sink and other high temperature parts.
2) Make sure Front Control wire lie flat on bottom cover and dressed around AC Power Cord.
Note : Keep Front Control Wire away from heat sinks and other high temperature parts.
3) Ensure Tweeter's tab is facing inside (towards CRT).
Note : Avoid wire being sandwich while docking rear cover.
H3
CAUTION : during Bottom
Front Control
Wire is placed
Front Control wire possible to get trap at
edge where beznet and bottom cover meet.
1) To prevent this, temporary place wire
behind DGC
Tweeter's
Insert Lead Assy, Speaker and
AC Power Cord into CRT
Ensure tweeter's
tab is facing
inside (towards
CRT) to avoid
wire being
sandwich while
docking rear
Lead Assy, Speaker
Front Control
AC Power
Bottom
Make sure Front Control wire lie flat on bottom cover
and dressed around AC Power Cord as shown.
=> Keep wire away from nearby heatsink.
Keep wires away from heatsink
CRT
Insert AC Power Cord in CRT support's
CAUTION:
Do not overpull the wires during dressing
--> avoid disconnection
of wire.

KV-21FT250
KV-21FT250
17
1) Dress DY Conn along Conn Assy, 5P (200V) as shown.
2) Dress DY Conn and Conn Assy, 5P (200V) with Purse Lock Ø5.
Note : Kept DY Conn & Conn Assy, 5P away from FBT area by a distance of 10mm or more.
1
2
DY
Earth Assy, Coating
Purse Lock Ø5
Conn Assy, 5P
(200V)
DY Conn
Conn Assy, 5P
DY Conn goes above Conn Assy, 5P
DY Conn goes underneath of Earth
Assy, Coating and Conn Assy, 5P
Make sure DY Conn is on the
right side of Earth Assy,
Purse Lock Ø5
≥ 10mm
Use heat sink height to
estimate purse lock location
Dress DY Conn and Conn Assy, 5P
(200V) with Purse Lock Ø5.
TVSR Requirement :
All wires must be kept away from
FBT area by a distance of 10mm or
more.
CAUTION:
Do not overpull the wires during dressing
--> avoid disconnection
of wire.
3
2-9. DY WIRE DRESSING

KV-21FT250
KV-21FT250
18
Purse lock dia.5
FBT
(G2)
FBT
Dress Earth Assy, Coating, Lead Assy, G2 & Focus with purse lock Purse Lock Ø5. as shown
Note : Keep Lead Assy, G2 away from HV Cable (min 1mm/kV)
Ensure Lead Assy, G2 is kept away from heat sinks
(Focus) ECA
CN704(C) CN705(C) CRT
SOCKET
Lead Assy, Focus
Lead Assy, G2
Purse Lock, dia.5
Figure b
Conn. Assy, 5P
Lead Assy,
Focus
Earth Assy,
Coating
Rear view of Lead Assy, Focus & G2,
Lead Assy,
G2
Use this as a reference to dress
ECA, Lead Assy, Focus & G2.
Dress tight at the portion to avoid
wire touches rear cover .
Keep Lead Assy, G2
away from Heat
Keep Lead Assy,
G2
away from HV
TVSR Requirement :
1. Spacing between HV cable and other conductive part’s surface is
1mm/kV or more.
2. Spacing between HV cable's and enclosure with ventilation or the edge
where terminal bracket and rear cover meet: 10 mm or more.
CAUTION:
Do not overpull the wires during dressing
--> avoid disconnection
of wire.
Figure a Figure c
Figure d
Safety
Operation
2-10.FBT WIRE DRESSING

KV-21FT250
KV-21FT250
19
.
45
OK
NG
HV
For Illustration only
DG
C
1) Dress HV cap assy with HV Holder as shown
Note: Make sure the specified position is being followed.
2) Dress HV holder at DGC with purse lock, Ø9 as shown
3) Using Yellow line (CRT Carbon line) as a reference to dress purse lock, Ø9.
CAUTION:
distance > 1mm/kv
distance < 1mm/kv
HV Cable Holder
180 ± 5 mm
Ensure HV Holder is beside DGC
to keep further distance from HV
Figure (c)
Figure (a) Figure (b)
Black
HV Cable
Purse Lock
Min. distance = 1mm/kv
Min. distance = 1mm/kv
For Illustration only
Min. distance =
0.5mm/kV
Purse Lock Ø9
DGC Conn
Dress HV Cable at inner
Place purse lock Ø9 after the exit of DGC Conn
TVSR Requirement :
1. Spacing between HV cable and other conductive
part’s surface is 1mm/kV or more.
2. Spacing between HV cable's and enclosure with
ventilation or the edge where terminal bracket and
rear cover meet: 10 mm or more.
3. Spacing between edge of anode cap and
conductive parts is 0.5mm/kV or more
CAUTION:
Do not overpull the wires during
dressing --> avoid disconnection
of wires.
Gate (2
positions) of HV
Safety
Operation
1) Dress AC Power Cord around PWB Bracket boss' as shown.
2) Dress AC Cord Holder at the Bottom Cover as shown.
3) Dress AC Power Cord with purse lock at rear cover as shown.
AC Power Cord
Purse Lock
Dress AC Power Cord
with purse lock at rear Cover.
AC Cord Holder Make sure AC Power Cord is
dressed between bottom cover
boss and rail guide
CAUTION:
Do not overpull the wires during dressing
--> avoid disconnection of wires.
2-11.HV CAP ASSEMBLY
2-12.AC POWER CORD TO REAR COVER

KV-21FT250
KV-21FT250
20
The following adjustments should be made when a complete realignment
is required or a new picture tube is installed.
These adjustments should be performed with rated power supply voltage
unless otherwise noted.
Set the controls as follows unless otherwise noted:
Picture control NORMAL
Brightness control NORMAL
SECTION 3: SET-UP ADJUSTMENTS
Perform the adjustments in order as follows:
1. Beam Landing
2. Convergence
3. Focus
4. Screen (G2)
5. White Balance
Note Test Equipment Required:
1. Color Bar Pattern Generator
2. Degausser
3. DC Power Supply
4. Digital Multimeter
3-1. BEAM LANDING ADJUSTMENT
Before beginning adjustment procedure:
1. Feed in the white pattern signal.
2. In order to reduce the geomagnetism on the set’s picture tube, face
it east or west.
Adjustment Procedure
1. Input a raster signal with the pattern generator.
2. Loosen the deflection yoke mounting screw, and set the purity
control to the center as shown below:
Purity control
3. Turn the raster signal of the pattern generator to green.
4. Move the deflection yoke backward, and adjust with the purity
control so that green is in the center and red and blue are even on
both sides.
Red
Blue
Green
5. Move the deflection yoke forward, and adjust so that the entire
screen becomes green.
6. Switch over the raster signal to red and blue and confirm the
condition.
7. When the position of the deflection yoke is determined, tighten it
with the deflection yoke mounting screw.
8. If landing at the corner is not right, adjust by using the disk
magnets.
Purity control
corrects this area. Disc magnets or rotatable
disc magnets correct these
areas (a-d).
Deflection yoke positioning
corrects these areas.
a
b
b
c
c
d
d
a
5. Oscilloscope
6. Landing Checker
7. XCV Adjuster