HP 16500B manual To check the video signals, Cable Pin Numbers

W A R N I N G

Vertical

Horizontal

Troubleshooting

To check the video signals

To check the video signals

Refer to chapter 6, "Replacing Assemblies," for instructions on how to remove or replace covers and assemblies.

Hazard voltages exist on the power supply, the CRT, and the CRT driver board. This procedure is to be performed by service-trained personnel aware of the hazards involved, such as fire and electrical shock.

1Turn off the instrument, then remove the bottom cover.

2On the color assembly, disconnect the cable that connects the microprocessor board to the color display assembly.

3Turn on the instrument, then wait for it to power up.

4Probe the cable for the horizontal sync, vertical sync, and display data signals.

The horizontal and vertical sync signals are TTL levels that resemble the figure.

The display data signals have a baseline of approximately −1.7 V and vary in amplitude from the baseline voltage to approximately 125 mV, depending on the characteristics of the colors displayed.

5Reconnect the cable, then return to the color display assembly flowchart.

Cable Pin Numbers

Pin Numbers	Signal
3	Vertical Sync
7	Horizontal Sync
21	Red Display Data
29	Green Display Data
37	Blue Display Data

Sync Signals

5–22