Blank Display - HP 8560A Service Manual

SOFT
KEY
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.)
SOFT KEY 83
b. Press
SOFT KEY
12.
If no failures were indicated in testing the A2 Controller, move the probe cable to A17J4.
SOFT KEY
SOFT KEY 84.
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
SOFT KEY
. The results will be sent to the printer.
, then SOFT KEY #4, and when the printout is complete,
The results will be sent to the printer.
#l and wait five seconds.