HP 8560A

9. Move the probe cable to A2J201, press SOFT KEY #l and wait five seconds.
16. Press SOFT KEY #4 . The results will be sent to the printer.
11. If a failure is indicated in any of these tests, the fault lies on the A2 Controller assembly.
to obtain more information:
a. Press the down arrow key one less time than the test number. (For example, press it
twice for the third test on the list.)
b. Press
SOFT KEY 83 , then SOFT KEY #4, and when the printout is complete,
SOFT KEY #6.
12. If no failures were indicated in testing the A2 Controller, move the probe cable to A17J4.
13. Press SOFT KEY #I and wait five seconds.
14. Press SOFT KEY 84. The results will be sent to the printer.
15. If no failure is indicated in the printout, check the high-voltage supplies as described
“High Voltage Supplies” in this chapter.
Blank Display
1. If the LED above the front-panel LINE switch is lit, most of the A6 Power Supply is
functioning properly.
2. Carefully check the voltages on the front-panel PROBE POWER jack. Be careful to avoid
shorting the pins together. See Figure 12-3.
3. Check that the fan is operating. If the PROBE POWER voltages are correct, and the fan
is turning, the A6 Power Supply is probably working properly.
4. If the rear-panel’s CRT
+llO VDC ON LED is lit, the high-voltage supplies should also
be operating. (The high-voltage supplies will be turned off if the HV SHUT-DOWN line
is low.) The A6 Power Supply feeds
+5 V to the A2 Controller through WI. The A2
assembly distributes this +5 V to the Al7 CRT Driver through W7. Al7 sends +5 V back
to A6 as the HV SHUT_DOWN signal over W8. As a result, A2, A17, Wl, W7, and W8
must all be in place for the high-voltage supplies to operate.
12-6 Display/Power Supply Section