Video amplifier board, Figure 2-11 . video amplifier pcb, block diagram, Chapter 2---system description – JVC Model 200 User Manual

Page 45

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Chapter 2---System Description

RED_VIDEO
GRN_VIDEO

BLU_VIDEO

BLANKING

G1 SUPPLY

G1 BIAS

RESTORE

ARC_GND

BLU_CATHODE

8

BLU_GRID1

9

BLU_GRID2

10

BLU_BEAM

16

BLU_HEAT-

7

BLU_HEAT+

6

ARC_GND

3

GRN _CATHODE 8

GRN _GRID1

9

GRN _GRID2

10

GRN_BEAM

14

GRN _HEAT-

7

GRN _HEAT+

6

ARC_GND

3

RED _CATHODE 8
RED _GRID1

9

RED _GRID2

10

RED_BEAM

12

RED _HEAT-

7

RED _HEAT+

6

ARC _GND

3

2
4
6

23

21

1
2

13 GRN_G2
15 BLU_G2

1 G2 SUPPLY

11 RED_G2

19 /SWEEP_OK

3 + 8OV
7 + 15V
5 + 6.2V
9 -15V

/VA_OK 18

J83

J68

J68

J85

J87

J68

J68

J84-1,
J86-1,
J88-1

J67

J68

J69

J68

From
VPB

From VPB

From HVPS

From RTG

From VPB

From
VPB

From HVPS

From HVDB

From
LVPS

To VPB

To RED
CRT

To VPB

To GRN
CRT

To VPB

To BLU
CRT

To VPB

To
HVPS

VIDEO
AMPLIFIER
BOARD

Figure 2-11. Video Amplifier PCB, Block Diagram.

CRT interface for Focus, heater voltages and ARC ground

The three CRT sockets are part of the VAB. They provide the
necessary interface for the input of the three CRTs. The Focus
voltage for each color is connected directly to the socket of each
CRT.

The VAB provides ARC grounds for each CRT which are used to
protect against arcing of the CRT anode supply.

IIC Interface

The VAB does not use the IIC interface. All adjustments are
accomplished by the control lines coming from the Video
Processor Board.

The Video Amplifier Board I/O

This section provides a description of the inputs to and outputs
from the VAB. The I/O descriptions are arranged by the
source/destination of the signal. The assembly communicated with
is used as the primary heading of each group of signals. Those
signals are subdivided into inputs and outputs. Input refers to an
Input to the VAB, output refers to an output from the VAB.

Model 200 Service Manual

2-31

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