Casio tv880b Service Manual
TV-880B (KX-518B)
INDEX
(For NTSC)
NOV. 1998
(without price)
TV-880B
R
CONTENTS
SPECIFICATIONS ......................................................................................... 1
BLOCK DIAGRAM ....................................................................................... 2
ADJUSTMENTS ............................................................................................ 3
PRINTED CIRCUIT BOARDS ....................................................................... 5
EXPLODED VIEW ......................................................................................... 7
PARTS LIST .................................................................................................. 8
SCHEMATIC DIAGRAMS ........................................................................... 11
SPECIFICATIONS
Item Specification
1. Type LCD Color Television
2. Reception Frequencies UHF: UHF band CH 14 – CH 69 (model B)
CH 21 – CH 69 (models C and N)
CH 21 – CH 68 (model D)
VHF: VHF band CH 2 – CH 13 (model B)
CH 2 – CH 12 (models C and N)
3. Display Element High resolution color liquid crystal display
(TI-STN Type)
4. Drive System Passive matrix system
5. Screen Size 2.3 inches
6. Backlight High luminance fluorescent material
7. Antenna Rod antenna (VHF, UHF)
8. Speaker 1 1/8ø inches (28 mm) × 1
9. Connection Terminals Earphone jack (3.5ø mini)
External power source jack (DC IN 6V)
Audio/Video input jack (3.5ø mini)
10. Power Supply 3-way power supply system
Batteries: 4 AA-size dry batteries
AC: AC adaptor AD-K64/AD-K65 (option)
Car battery: Car adaptor CA-K65 (option)
11. Power Consumption Approx. 3.1 W
Approx. 3.4 W (Model B only)
12. Ambient Temperature Range 32°F (0°C) ~ 104°F (40°C)
13. Dimensions 3 1/4" (W) × 1 7/16" (D) × 5 1/16" (H) inches
83 (W) × 36 (D) × 128 (H) mm
14. Weight Approx. 6.7 oz 190 g (excluding batteries)
— 1 —
— 2 —
TUNER
(TEAA1)
PRE
AMP
ANT
SAW
FILTER
VIF/SIF
(M51348FP)
POWER SW
BAND SW
DC DC
CONVERTER
TRANS
BATTERY 1.5 V × 4
AC ADAPTOR 6V
EXTERNAL VIDEO
EXTERNAL AUDIO
EAR PHONE
SP
AUDIO2
VCC1-1
VCC2
VCC2 (4.0 V)
VCC7 (40 V)
VEE1 (—5 V)
AV
JACK
AUDIO AMP
NJM2070M
VCC2
TU
VCC2-8
AFI
UV
HL
A MUTF
MODULE
VIDEO2
AVB
VCC7 BT
VCC2 (4.7 V)
VCC1-1
VEE1VCC7
CHROMA
M52042FP
TUNING
BT GEN
BA 10358
VOLTAGE
SUPLLY
FOR LCD
DRIVER
A D CONVERTER
CONTROLLER
OM6006
INVERTER
IRANS
BL-PCB
LAMP
VCC1-1 GND
CN710
CN950
LCD DRIVER 5151
BTBVBS
U. V
AUDIO1
VIDEO1
A-MUTE
AFT
AUDIO1
VIDEO1
RGB
HD
C-SYNC
CN700
LCD
LCM
L-PCB
LCD DRIVER
051
LCD DRIVER
051
VCC2-0 GND
V1. V3. V0. V4. VO
CK1. CK2
D1~ 6
SNB STR
CNB2. CDB2. CFB2
EN1. EN2
MODULE
POWER
SUPPLY
BLOCK DIAGRAM
ADJUSTMENTS
1. VCC2 adjustment, VCC2-3, VCC7, VEE1 voltage check
2. LLD coil adjustment
3. Free running frequency adjustment
4. Contrast adjustment
5. TINT pot adjustment
Preparations
1. Connect AVB (CP725) to GND.
2. Set SW100 on UHF mode.
Adjustment procedures
1. VCC2 adjustment, VCC2-3, VCC7, VEE1 voltage check
• Condition
Power supply: Vcc1-1 = 5.0 ± 0.05 [V]
• Adjustment
Apply 5.0 ± 0.05 [V] on Vcc1-1 (CP101).
Adjust VR100 so that Vcc voltage becomes 4.90 ± 0.02 [V].
• Checking
VCC2-3 (CP-105) = 3.87 ~ 4.13 [V]
VCC7 (CP103) = 36.0 ~ 44.0 [V]
VEE1 (CP104) = –4.5 ~ –5.5 [V]
2. LLD coil adjustment
• Conditions
(1)Signals
Broadcasting system: M/M
Color system: NTSC color bar
(2)Signal level
Input electric field: 40 ± 5dBµ (IF AGC full gain), P/S = 10dB
(3)Other conditions
US IF (Input electric field: terminated with 75-ohm resistance)
Power supply: Vcc1-1 = 5.0 ± 0.05 [V]
• Adjustment
Monitor video detection signal (CP238) via a low-pass filter of 100 kHz cutoff frequency and adjust
LLD coil T200 so that its DC level is minimum (waveform’s amplitude is maximum).
(Reference: C= 1500 pF, R = 1 Kohm)
• Confirmation
There should be no waveform distortion (erroneous synchronization, etc.), under sensitivity (video
detector output level is abnormally small, etc.).
3. Free running frequency adjustment
• Conditions
(1)Signal
No signal (NTSC standard signal should be applied only at synchronous check)
(2)Signal level
Input electric field only at synchronous check: 70 dBµ (terminated with 75-ohm resistance), P/S = 10 dB
(3)Other conditions
US IF input only at synchronous check (input electric field with 75-ohm termination).
Connect SYF terminal (CP729) and VCC2-7.
Power supply: Vcc1-1 = 5.0 ± 0.05 [V]
Room temperature: 20 ± 10 [°C]
— 3 —
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