HP 54540 Series - To Check CRT Monitor Signals; To Check Probe Power Outputs

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Chapter 5: Troubleshooting
To check probe power outputs
To check probe power outputs
The two probe power outputs are on the rear panel.
Use the table and figure to the right to | Pin
check the power output at the
connectors. The +12 V and -12 V
supplies come directly from the power
supply and the +6 V and -6 V supplies
are developed in three- terminal
regulators on the main assembly.
Syne bFon =
To check CRT monitor signals
This test checks for the signals between the main assembly and the CRT Monitor.
Remove the top cover.
Check the CRT Monitor input cable for the signals and supplies listed in the table
below. The cable is the wide ribbon cable connecting the monitor PC board to the
main assembly.
The video signal is an analog signal from an eight-bit digital-to-analog converter.
Check for activity on that line.
CRT Monitor Input Cable Pin Assignments
Pin — Supply/Signal Pin — Supply/Signal Pin — Supply/Signal Pin — Supply/Signal
1 +5 V (Digital) 6 Ground nt VERT_SYNC 16 Video
2 +12 V (Display) 7 +12 V (Display) 12 +12 V (Display) 7 Ground
3 Ground 8 Ground 13 Ground 18 NC
4 Ground 9 +12 V (Display) 14 Ground 19 Ground
5 +12 V (Display) 10 HOR_SYNC 15 Ground 20 +5 V (Digital)
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