DOWNLOAD Sony KV-AR25M81A Service Manual ↓ Size: 5.04 MB | Pages: 89 in PDF or view online for FREE

Model
KV-AR25M81A
Pages
89
Size
5.04 MB
Type
PDF
Document
Service Manual
Brand
Device
TV
File
kv-ar25m81a.pdf
Date

Sony KV-AR25M81A Service Manual ▷ View online

– 6 –
KV-AR25M81A
RM-952
5. 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 as shown below when the diagnostic
screen is being displayed.
Channel [8]
/ 0
[Quitting Self-diagnostic screen]
To quit the entire self-diagnostic screen, turn off the power switch on the remote commander or the main unit.
6. SELF-DIANOSTIC CIRCUIT
[+B overcurrent ªOCPº]
Occurs when an overcurrent on the +B(135) line is detected by Q604. If Q604 go to ON
and the voltage to pin 18 of IC301 should go down when V.SYNC is more than seven
verticals in a period, the unit will automatically turn off.
[Vertical deflection stopped]
Occurs when an absence of the vertical deflection pulse is detected by Q509 and IC001
shut down the power supply.
[Vertical deflection overcurrent]
Occurs when an overcurrent on V drive line is detected by Q507. Power supply will be
shut down when detect this by IC001.
[White balance failure]
If the RGB levels* do not balance or become low level within 5 seconds, this error will be
detected by IC301. TV will stay on, but there will be no picture.
* (Refers to the RGB levels of the AKB detection Ref pulse that detects IK.)
IC301
Y/CHROMA JUNGLE
FROM
CRT
[V] Q509/507
IC001
SYSTEM
IC003
MEMORY
IK-IN
MP/
PROTECT
O-LED
IO-8DAT
B-DAT
IO-SDAT
5
21
18
51
46
SDA 35
FROM
[+B] Q604 C6
45
– 7 –
KV-AR25M81A
RM-952
SECTION 1
DISASSEMBLY
1-1.
REAR COVER REMOVAL
1-2.
SPEAKER BLOCK ASSY REMOVAL
1-3.
CHASSIS ASSY REMOVAL
1 Nine screws
     (+BVTP 4 
× 16)
2 Rear cover   
1 Four screws
     (Washer head)
     (+P 4
×16 )
2 Speaker Block Assy
1-4.
SERVICE POSITION
1-6.
V1 BOARD REMOVAL
1-5.
TERMINAL BRACKET AND J BOARD
REMOVAL
3 J Board
4 Two screw
     (+BVTP 3 
× 12)
5 Terminal bracket
2 Two screws
     (+BVTP 3 
× 12)
1 One screw
     (+BVTP 4 
× 16)
6 Two Hooks
2 V1 Board
1 Two claws
– 8 –
KV-AR25M81A
RM-952
1-9.
PICTURE TUBE  REMOVAL
Note:
• Please make sure the TV set is not in standing position before removing necessary CRT support located on bottom
right and left.
1) Place the TV set with the CRT face down on a cushion jig.
2) Removal the rear cover.
3) Removal the Speaker Block Assy.
1-8.
A AND B9 BOARDS REMOVAL
1-7.
H1 AND H2 BOARDS REMOVAL
5 Cover, H
6 H2 Board
4 Two hooks
3 Four hooks
3 H1 Board
1 Two screws
     (Washer head)
     (+BVTP 3 x 12)
5 A Board
4 B9 Board
1 One screw
(Washer head)
(+BVTAP 3 x 12)
2 One screw
(Washer head)
(+BVTAP 3 x 12)
3 Two screws
(Washer head)
(+BVTAP 3 x 12)
!∞ Nut, locking
!¡ Holder, DGC(2) 
     Removal
q;
 Spring Tension(2) 
     Removal
8 Loosen the Neck Assembly
fixing screw and removal
7 VM1 Board Removal
9 Chassis Assy Removal
5 C6 Board Removal
6 Loosen the Neck Assembly
fixing screw and removal
qs
 Degaussing Coil
!£ Band, DGC Removal
4 Anode Cap Removal
qf
 Earth Coating Assy
– 9 –
KV-AR25M81A
RM-952
• REMOVAL OF ANODE-CAP
Note:
• After removing the anode, short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT
shield or carbon paint on the CRT.
• REMOVING PROCEDURES
Turn up one side of the rubber cap in the direction
indicated by the arrow 
a.
Using a thumb pull up the rubber cap firmly in the direc-
tion indicated by the arrow 
b.
When one side of the rubber cap is separated from the
anode button,  the anode-cap can be removed by
turning up the rubber cap and pulling it up in the
direction of the arrow 
c.
• HOW TO HANDLE AN ANODE-CAP
Do not damage the surface of anode-caps with
sharp shaped objects.
Do not press the rubber too hard so as not to
damage the inside of anode-cap.
A metal fitting called the shatter-hook terminal is
built into the rubber.
Do not turn the foot of rubber over too hard.
The shatter-hook terminal will stick out or damage
the rubber.
a
a
b
b
c
anode button
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