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JVC Model 200 User Manual

Page 46

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Chapter 2---System Description

Table 2-8. Video Amplifier I/O signals

Video Processor Board

INPUTS DESCRIPTION

RED_VIDEO

GRN_VIDEO

BLU_VIDEO

Video preamp signals. About 0.5 VPP

G1_BIAS

Brightness control line. 0 to 5 V DC

RED_G2

GRN_G2

BLU_G2

Black level (G2) control lines 0 to 3.1 V

RESTORE

Video DC restoration pulse. logic HC positive going 4% duty cycle

OUTPUTS DESCRIPTION

/VA_OK

VAB status line. Low = good VAB. High = Bad VAB (This signal is
called /HV_ENABLE at the HVPS).

RED_BEAM

GRN_BEAM

BLU_BEAM

Cathode beam current lines. about 1 volt per 100 UA

High Voltage Power Supply

INPUTS DESCRIPTION

G1_SUPPLY Supply for G1 grid of CRTs. About -200 V

G2_SUPPLY Supply for G2 (screen) grid of CRTs. About 1200 V

RED_FOCUS
GRN_FOCUS
BLU_FOCUS

Focus supply for CRTs. about 7 KV

OUTPUTS DESCRIPTION

ARC_GND

CRT ground (anode supply return line)

Horizontal/Vertical Deflection Board

INPUTS DESCRIPTION

/SWEEP_OK

Deflection detection line. open collector, low = good deflection

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Model 200 Service Manual