Tektronix WVR4000, Руководство по обслуживанию

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Maintenance
Figure 2: Backplane board power supply test points
Front Panel Button
Troubleshooting
Perform this test if the power supplies are good, but none of the buttons are lit or
responding to presses.
1. Cycle the power to the unit. Immediately after power up, three buttons
(GAIN, SWEEP, and MAG) should be lit continuously for about a second.
Another button or two will begin to light brie
fl y and one at a time before all
buttons go out for a number of seconds while the display prints out a couple
lines of text. Normal boot time is approximately 30 seconds. The initial
sequence of lights, just before they all go out, indicates that the front panel
processor is booting normally.
2. If the buttons are not lit, check the 10 pin cable from the keypad to the main
board J1. If the cable is connected and good, then replace the front panel
assembly.
3. If the buttons do not go out after a second or so, and continue to blink in
a walking sequence, this indicates that the front panel processor has not
received any communications from the Main board host processor. Check the
10 pin cable from the keypad to the main board J1 for proper seating and that
none of the pins in the connector are pulled out. If the connector/cable looks
okay, using a known good Front Panel is the next best troubleshooting tactic
to isolate which board (Front Panel or Main) is at fault.
4. If the buttons light as expected and the unit appears to complete booting, but
the keys are nonresponsive, check to see if the fault light is on (red LED
18 WVR4000 and WVR5000 Service Manual