Casio TV-350C Service manual
(with price)
INDEX
POCKET TELEVISION
TV-350C
OCTOBER 1994
Page
Specifications.............................................................................................2
Block Diagram ...........................................................................................3
Adjustment
Linear PCB......................................................................................... 4
Printed Circuit Boards................................................................................8
Wiring Diagram........................................................................................10
Electrical Parts List ..................................................................................11
Mechanical Parts List...............................................................................17
Exploded Views / Disassembly................................................................ 18
Schematic Diagrams and Waveforms .....................................................19
R
SPECIFICATIONS
Item Specification
Reception Channels VHF: Ch 2 ~ 12 ch UHF: Ch 21 ~ 69
Power Voltage DC 6.0 V
Power Consumption Approx. 3.0 W
Current Consumption Approx. 500 mA
Battery Life (with alkaline batteries) Approx. 3.0 hours
Batteries : 4 AA size batteries
Power Supply Car adaptor : CA-K65
AC adaptor : AD-K65
Connection Terminals Earphone jack : 3.5ø mini
External power jack : 6.0 V DC IN
Screen Size 1.6 inches
No. of Picture Element 39,600 (110 × 360) dots
Dimensions 122 mm (H) × 66 mm (ø)
Weight 210 g excluding batteries
7.4 oz excluding batteries
Options AC adaptor : AD-K65
Car adaptor : CA-K65
— 2 —
Antenna
BLOCK DIAGRAM
Power
Supply
1 TU200 2 Q200
IF Amp.Tuner
7
IC500
Tuning
Voltage
Generator
VCC2 (3.95V±0.02V)
VCC6 (30.5 ~ 39.0V)
VCC7 (53.5 ~ 72.5V)
VEE1 (-6.3 ~ -7.9V)
VR800
Brightness
Control
3 IC200
Video
Sound Det.
FM
AFT Circuit
AGC Circuit
5
6
8 Q800 ~ Q806
IC300
Chroma
Circuit
IC700
OSC
Display
Control
A-D Converter
Auto-Tuning
Control
Display
Voltage
Generator
VR600
Volume
Control
4 IC600 Speaker
Audio
Amp.
Common
Driver
LCD
Segment
Driver
1 — Color Tuner: TU200 TEPE5-01
Selects a desired radio wave and changes it to the video IF signal.
2 — Video IF Amp.: Q200 2SC4238
Amplifies the video IF signal output from the tuner TU by 10 times (20dB).
3 — Video Det./Sound Det./FM Det./AFT/AGC: IC200 M51348FP
Eliminates the carrier wave in the video IF signal, and picks up the video signal and the sound IF signal.
Also, the sound signal is picked up from the sound IF signal by FM detection.
4 — Audio Amp.: IC600 NJM2070M
Sound amplification.
5 — Chroma Circuit: IC300 M52045FP
Generates the tricolor (red, green, and blue) from the video signal.
6 — OSC/A-D Converter/Display control/ Auto-Tuning Control : IC700 MSM662502 GSK-640F
Converts the color signal into a digital signal.
Also, generates the clock pulse for the display and controls the display.
7 — Tuning Voltage Generator: IC500 MSC1169MS-K
Generates the tuning voltage with the tuning pulse (TU) output from 6.
8 — Display Voltage Generator: Q800 ~ Q806 2SB1218A-R, 2SD1824R, S × 2, 2SD1819A-R × 5,
2SD1824-5
Generates the display voltages V0 ~ V4 with VEE1 and VCC7 outputs from the power supply.
— 3 —
ADJUSTMENT
Linear PCB
1) Items to Be Adjusted
Item Measuring Instrument
VCC2 voltage setting Voltmeter
Video detection coil adjustment TV signal generator, Pattern generator, Oscilloscope,
Low-pass filter
AFT coil adjustment Sweep generator, Oscilloscope, Voltmeter
Contrast adjustment TV signal generator, Pattern generator, Oscilloscope
AGC adjustment TV signal generator, Pattern generator, IF levelmeter
Clock adjustment Voltmeter
2) Adjustment and Test Point Locations
TOP VIEW
T201T200
VR100
— 4 —
Pad IF
BOTTOM VIEW
TP7
VR200
TP2
TP3
TP4
VR700
TP6
VR301
TP5
VR300
3) Equipment Connection / Procedure
VCC2 Voltage Setting
TV-350
Set
Voltmeter
Output
TP1
Input Input Input Output Output
Connection Point Signal Connection Point
Adjust Result
VR100
Voltmeter
TP1
Adjust for 3.95 ± 0.02V
reading on voltmeter.
— 5 —
* Open soldering pad IF.
Pattern
generator
Signal
generator
Video Detection Coil Adjsutment
TV-350
Set
Input Output
Oscilloscope
Low-pass
filter
TP2
Input Input Input Output Output
Connection Point Signal Connection Point
Adjust Result
TP3
Pattern
generator
Signal
generator
TP2 T200 TP3
Color bar
38.9MHz
41 ± 3dBµ
Low-pass filter
Oscilloscope
AFT Coil Adjustment
* Open soldering pad IF.
Sweep
generator
Input
TP2
TV-350
Set
Oscilloscope Voltmeter
Output
TP4
R=180 ohm
C=0.01 µF
Adjust for DC level at mini-
38.9 ± 5MHz
Sweep
generator
(Sweep) Marker:
TP2 T201 TP4
38.9MHz
70dBµ
* Open soldering pad IF.
Pattern
generator
Pattern
generator
Signal
TP2 VR300 TP5
Color bar
38.9MHz
70dBµ
generator
Signal
generator
Voltmeter
Oscilloscope
Contrast Adjustment
TV-350
Set
Input
TP2
Oscilloscope
Adjust for 1.8 ± 0.2V reading on
voltmeter.
Confirm that the marker is at
the middle of S-curve on oscilloscope.
Oscilloscope
Low-pass
filter
Output
TP5
R=100 ohm
C=2700 pF
Adjust step form wave to read
0.75 ± 0.05 Vp-p.
— 6 —
AGC Adjustment
Pattern
generator
Signal
generator
TV-350
Set
Input Output
TP7
Input Input Input Output Output
Connection Point Signal Connection Point
Adjust Result
TP2
Pattern
generator
TV Signal
TP7 TP2
Color bar
65 ± 5 dBµ
VR200
IF levelmeter
generator
Tint Adjustment
* Open soldering pad IF.
Pattern
generator
Pattern
generator
Signal
TP2 TP3
Signal
generator
Color bar
38.9MHz
70 dBµ
Input
TP2
VR301
TV-350
Set
Output
TP3
Low-pass filter
Oscilloscope
generator
IF levelmeter
Adjust for 81 ± 1 dBµ reading
on the IF levelmeter
Oscilloscope
Low-pass
filter
R=100 ohm
C=2700 pF
Adjust VR301 so that the difference between pulse A and
B is less that 0.1V.
Pulse A Pulse B
Clock Adjustment
TV-350
Set
Output
TP6
VR700 TP6
Voltmeter
— 7 —
Voltmeter
Adjust for 1.00 ± 0.05V
reading on voltmeter.
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