Chapter 5---Electronics

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.

G1_SUPPLY - supply for G1 grid on CRTs from High Voltage Power Supply (about -150 V).

G1_BIAS - brightness control line from Video Processor PCB (0-5 VDC). RGB_G2 - G2 (black level) control lines from Video Processor PCB (0-3.1 V).

G2_SUPPLY - supply for G2 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.

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

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Model 250 Service Manual

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Image 99
JVC 250 service manual Video Amplifier PCB Inputs