Keysight N5224B, Service Manual

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4-20 Keysight N5224B/25B Service Guide
Troubleshooting
Front Panel Troubleshooting
4-
Checking the RPG (Front Panel Knob)
To check the RPG knob:
1. Rotate the knob clockwise (cw) and check for a fluid movement of
numbers on the analyzer display and verify that Knob Rotate CW is
displayed. Refer to Figure 4-5 .
Figure 4-5 RPG Knob Clockwise Verification
2. Rotate the knob counter clockwise (ccw) and check for a fluid movement
of numbers on the analyzer display and verify that Knob Rotate CCW is
displayed.
3. Press the knob and verify that Knob Click is displayed.
4. If the movement of numbers is not smooth or no numbers appear at all,
suspect a faulty RPG board or the A1 front panel interface board. To
replace the RPG board, refer to “Removing the RPG Assembly” on
page 7-11 . To replace the A1 front panel interface board, refer to
“Removing the A1 Front Panel Interface Board and Keypad Assembly” on
page 7-11 .
5. When done to close the Key Label window and return to the instrument
display, press Preset three times.
A3 Display Test
The display should be bright with all annotations and text readable. The display
test allows you to check for non-functioning pixels and other problems.
This section assumes you have completed the introduction and opened the
Front Panel Key Test Utility window. Refer to “Front Panel Keypad and RPG
Test” on page 4-17 .
If the display is dark, refer to “Removing the A3 Display Assembly and the
Touchscreen” on page 7-13 and to “Removing the Touchscreen Controller
Board” on page 7-12 .