Cable Pin Numbers - HP 16500A Service Manual

HP 16500A/16501A - Service
Video Signals Check
This procedure checks the video signals.
1. Turn off the instrument, then remove the bottom cover.
2. On the color module, disconnect the cable that connects the microprocessor board to the color
module. Refer to figure 6-30 for the cable location.
3. Load the operating system into one disk drive and apply power to the instrument. Allow enough
time for the operating system to load.
4. Probe the cable for the horizontal sync, vertical sync, and display data signals. The cable pin
numbers are listed in table 6-1.
The horizontal and vertical sync signals are TTL levels that resemble figure 6-31.
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.
5. Reconnect the cable, then return to the color module flowchart.
6-34
Table 6-1. Cable Pin Numbers
Pin Numbers Signal
3 Horizontal Sync
7 Vertical Sync
21 Red Display Data
29 Green Display Data
37 Blue Display Data