Display Distortion; Probe Power Socket - HP 8560A Service Manual

5. If all of the power supply indicators along the outside edge of,the A2 Controller assembly
are lit, the A6 Power Supply is probably working properly.
6. Press FREQUENCY, 0, (GHz).
7. Allow the analyzer to warm-up for at least one minute.
8. While observing the display, set the m switch off. If a green dot moves across the
display, the CRT is probably working properly; troubleshoot either the A2 Controller or the
Al7 CRT Driver.
9. If a green dot does not move across the display, the A2 Controller, A6Al HV Module, Al7
CRT Driver, or A18Vl CRT might be at fault.

Display Distortion

The HP 8560A uses a vector display. The graticule lines, traces, and characters are composed
of a series of straight lines ("vectors") placed end-to-end. If the vectors do not begin and
end at the proper points, the display appears distorted, but in focus. Symptoms range
from characters appearing elongated and graticule lines not meeting squarely, to an entirely
unreadable display.
1. Use the CRT ADJ PATTERN to check for distortion. Press (CAL), MORE, and
CRT ADJ PATTERN.
Adjustment in Chapter 2 to test the function of the A2 assembly.
2. If there is distortion along with slight focus degradation, but the graticule lines meet (not
necessarily squarely), the Al7 CRT Driver, CRT, DDD/TRACE ALIGN adjustments, or
cable connections might be at fault.
F R O N T V I E W
, +15v
I
Figure 12-3. Probe Power Socket
If vector distortion (described above) occurs, perform the Display
I
I
I
Display/Power Supply Section 12-7
S K 1 1 2 2