JVC 250 User Manual

Page 99

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Chapter 5---Electronics

5-44

Model 250 Service Manual

Video Amplifier PCB - Inputs

RGB_VIDEO - image pre-amp signals from the Video Processor PCB (about 0.5
Vpp).

RESTORE - image DC restorations pulse from Video Processor PCB, logic level
positive going 4% duty cycle.

BLANKING - Blanking signal, logic F type.

G

1

_SUPPLY - supply for G

1

grid on CRTs from High Voltage Power Supply

(about -150 V).

G

1

_BIAS - brightness control line from Video Processor PCB (0-5 VDC).

RGB_G

2

- G

2

(black level) control lines from Video Processor PCB (0-3.1 V).

G

2

_SUPPLY - supply for G

2

grid on CRTs from High Voltage Power Supply

(about 1200 V).

RGB_ FOCUS - Focus supply for CRTs from the High Voltage Power Supply
(approximately 7 kV).

SWEEP_OK - deflection status line from the Horizontal Vertical Deflection PCB.

+80 V - from the Low Voltage Power Supply

±15 V - input power for the analog circuitry from the Low Voltage Power Supply.

6.2 V - input power for the CRT filaments heaters from the Low Voltage Power
Supply.

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