ViewSonic G90fB-4 User Manual

Service Manual
ViewSonic G90fB-4
Model No. VS10794
19” Digital Controlled Color Monitor
(G90fB-4_SM Rev. 1a Jan. 2006)
ViewSonic
®
381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583

ViewSonic G90fB-4 Specifications

General

Screen Size	19 inches
Display Type	CRT
Max Resolution	1920 x 1440
Refresh Rate	85 Hz
Aspect Ratio	4:3
Viewable Size	18 inches
Vertical Refresh Rate	50 - 160 Hz
Input Signal	Analog RGB
Dot Pitch	0.25 mm
Horizontal Refresh Rate	30 - 85 kHz

Summary

Precautions and Safety Notices

Safety Check and Hazards

Covers basic safety, fire, and shock hazards during servicing, including warnings and cautions.

Leakage Current Checks

Details procedures for cold and hot leakage current testing to ensure electrical safety.

Implosion Protection and X-Radiation Safety

Discusses CRT implosion protection systems and necessary X-radiation safety precautions.

Circuit Description

Microcontroller and Deflection Circuit

Describes the microcontroller, sync processor, reset circuit, and X-ray protection features.

Adjusting Procedure

Adjustment Conditions and Methods

Purity and Convergence Adjustments

Troubleshooting Flow Chart

Raster and DDC Issues

Flowcharts for diagnosing no raster or abnormal DDC (Plug & Play) communication issues.

Video and Blanking Issues

Flowcharts for troubleshooting abnormal video levels or problems with screen blanking.

Signal and Width Issues

Flowcharts for diagnosing no signal on screen or abnormal horizontal width problems.

Linearity, Size, Center, Distortion, Focus

Flowcharts for addressing linearity, size, center, distortion, and focus issues.

Power Supply Troubleshooting

Flowchart for diagnosing and resolving power supply circuit problems.

Schematic Diagrams

CPU Schematic

Power Supply Schematic

Output Stage Schematic

Video Circuit Schematic