Block Diagram - Casio JY-70B Service Manual & Parts List

Antenna
1 TU200
Tuner
7 IC500
Tuning
Voltage
Generator
VCC2 (3.95 ± 0.02 V)
Power
VCC7 (34.2 ~ 41.8 V)
Supply
VEE1 (– 6.03 ~ – 7.37 V)
1 — Color Tuner: TU200 TEAA1(JY-70B) / TEPE5-01(JY-70C/N/I)
Selects a desired radio wave and changes it to the video IF signal.
2 — Video IF Amp.: Q200 2SC3082
Amplifies the video IF signal output from the tuner TU by 10 times (20 dB).
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 M52042FP
Generates the tricolor (red, green, and blue) from the video signal.
6 — Osc./A-D Converter/Display Control/ Auto-Tuning Control : IC700 ML9661GA-6006
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 BA10358F
Generates the tuning voltage with the tuning pulse (TU) output from 6.
8 — Display Voltage Generator: Q800 ~ Q803 Q805 Q806 2SD1819A, 2SB1218A, 2SD1149S
Generates the display voltages V0 ~ V4 with VEE1 and VCC7 outputs from the power supply.

BLOCK DIAGRAM

3 IC200
2 Q200
Video
Sound
IF Amp. FM
AFT Circuit
AGC Circuit
5
Chroma
Circuit
6
Osc.
Display
Control
A-D Converter
Auto-Tuning
Control
8 Q800 ~ Q803, Q805, Q806
VR800
Display
Voltage
Generator
Brightness
Control
— 2 —
VR600
Det.
Volume
Control
IC300
Common
Driver
IC700
4 IC600 Speaker
Audio
Amp.
LCD
Segment
Driver