Casio TV-600B Service Manual
(with price)
INDEX
POCKET TELEVISION
TV-600B
DECEMBER 1994
Page
Specifications.............................................................................................1
Block Diagram ...........................................................................................2
Circuit Description......................................................................................3
Adjustment
Linear PCB..........................................................................................5
A/D PCB..............................................................................................9
Troubleshooting.......................................................................................10
Printed Circuit Boards..............................................................................11
Wiring Diagram........................................................................................15
Exploded View / Disassembly..................................................................16
Electrical Parts List ..................................................................................17
Mechanical Parts List...............................................................................23
IC and Transistor Lead Identification .......................................................24
Schematic Diagrams and Waveforms .....................................................26
R
CIRCUIT DESCRIPTION
TUNING VOLTAGE GENERATOR
BT
BS
16
15
BS
Vcc
VCC6
IC500 MSC1169MS-K
14
BT
13
IN
12
OUT
11
TU
10
H/L
TU
H/L
BU
9
U/V
VREFU1U2
1
2
VL1
VL2
VH1
VH2
GND
3
4
5
6
7
8
VREF
R500R501R502
GND
Figure 1
This circuit generates the DC tuning voltage BT for selecting a channel with a TU pulse being output from
IC700.
IC500 has 3 circuits for converting pulses to voltages; it selects one of VHF-L, VHF-H, or UHF, and
causes the tuning voltage to be output from the OUT terminal (pin 12). Figure 2 and Table 1 show the
conditions for selection.
IC500
TU
11
VHF
-L
VHF
-H
UHF
910
U/V H/L
Figure 2
12
OUT(BT)
— 3 —
Inputs
U/V
L
L
H
H
H/L
L
VHF-L receiving
H
VHF-H receiving
L
UHF receiving
H
UHF receiving
Table 1
Function
POWER SUPPLY
Vref
VCC1-1
C100
D100
C105
CP100
VR100
R101
C135
Q100
Q101
R111
R102
C140
Q111
R115
C145
R117
Figure 3
1
9
CP104
T100
GND
VCC2-2
L102
D155
32
4
5
D152
6
7
D150
D152
C112
L101
C110
C113
VCC2-3
R133
VCC7
CP108
VCC6
CP107
VCC2
CP109
VEE1
CP110
C115
C114
The power supply consists of a DC-DC converter and causes the voltages to be output as shown in Table 2.
Name Voltage Function
VCC2 3.95 ± 0.02 V Main voltage
VCC6 30.5 ~ 39.0 V Tuning voltage
VCC7 53.5 ~ 72.5 V Tuning voltage/Display voltage
VEE1 –6.3 ~ –7.9 V Display voltage
Table 2
— 4 —
ADJUSTMENT
LINEAR PCB
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
Adjustment And Test Point Locations
T201
T200
Top View
— 5 —
TP7
VR100
TP5
VR300
TP2
TP1
PadIF
VR200
TP3
Bottom View
Equipment Connection / Adjustment Procedure
VCC2 Voltage Setting
TV-600
Set
TP4
Voltmeter
Output
TP1
Input Input Input Output Output
Connection Point Signal Connection Point
Adjust Result
VR100
Voltmeter
— 6 —
TP1
Adjust for 3.95 ± 0.02 V
reading on voltmeter.
A/D PCB
Item to Be Adjusted
Item Measuring Instrument
Clock adjustment Voltmeter
Adjustment And Test Point Locations
TOP VIEW
TP6
Equipment Connection / Procedure
Clock Adjustment
TV-600
Set
Output
TP6
Input Input Input Output Output
Connection Point Signal Connection Point
Adjust Result
VR700
Voltmeter
Voltmeter
TP6
VR700
Adjust for 2.05 ± 0.05 V reading on voltmeter.
— 9 —
Loading...