Tektronix Webcam 070-8030-01 User Manual

Page of 652
Troubleshooting Procedures
6–30
1780R-Series Service Manual
Touch Panel Sensitivity Adjustment (A9R292)
Test Oscilloscope:
See Equipment Required List for the Performance Verification
or Adjustment Procedures.
1. Check that the 1780R-Series instrument POWER switch is set to OFF
(STANDBY).
2. Remove the CRT Panel and CRT Frame Outer Bezel by using the Graticule
Light Removal procedure as a guide. Disconnect the PROBE wire where it
pugs into the PROBE BNC connector.
3. Connect a 10X probe from the test oscilloscope to pin 1 on A10–U520 on
the MPU Annex board.
4. Set the test oscilloscope controls to 2 V/Div and 5 ms/Div.
5. Set the 1780R-Series POWER switch and CONFIGURE button to ON.
6. ADJUST Touch Panel Sensitivity (A9R292) in a direction that minimizes
the amplitude of the touch panel pulses displayed on the test oscilloscope
CRT. Turn A9R292 in the opposite direction until all the touch panel pulses
are at maximum amplitude. Then, continue to turn the adjustment two
notches past the maximum amplitude point for optimum sensitivity.
NOTE. When adjusting A9R292, keep the ambient light level as low as possible
by shading the back of the front touch panel. (Too much light will adversely
affect the adjustment sensitivity setting.)
7. Set the POWER switch to STANDBY.
8. Disconnect the 10X probe from the MPU Annex board.
9. Reconnect the wire to the PROBE BNC connector when reassembling the
CRT Frame Outer Bezel to the Front Frame Section.
10. Install the CRT panel and control knobs.
Equipment Required List
Procedure