Front Panel Connectors - HP 8340B Manual

3.
All
LEDs and annunciators should light
and remain on as
long
as you press
[INSTR PRESET].
4.
If any LED or annunciator fails to light, use
Figure G-2 to identify the appropriate assembly.
ALPHANUMERIC DISPLAY TEST
1.
To
activate the display self test diagnostic
mode, press
[SHIFT]
[FREE RUN].
2.
You should see
the following:
a.
For three seconds, the
ENTRY display shows
DISPLAY RAM TEST PASSED
b.
For the next three seconds, the
ENTRY
display shows
DISPLAY CHECKSUM
=
3A.
c.
For six seconds,
all numeric display segments light, and all
ENTRY
display dots
flash.
d.
The entire available character set
scrolls
across the
displays, and continues to
scroll until the
diagnostic routine
is
terminated with
[SHIFT] [M5].
3.
If
you note any discrepancies, refer to
the A1, A2, and
A3 assembly-level troubleshooting
pro¬
cedures.
KEY AND RPG TEST
1.
With the power switch set to
STANDBY
(no fan noise), check the mechanical action of each key.
Check for height differences, unusual sounds when pressed, and differences
in
the force required
to depress each
key.
2.
Check that the front panel knob rotates smoothly.
3.
Turn
the
power
switch
on
and press each front panel key. Check for the
proper
ENTRY
display
message,
and that the appropriate LEDs and annunciators light.
NOTE:
Some keys require that other keys are pressed first (e.g. the GHz and dBm terminators).
4.
Press
[INSTR PRESET] [POWER LEVEL]
and slowly rotate the front panel knob
in
both
direc¬
tions.
Watch for
a 0.05
dB increment (clockwise) and
decrement (counter-clockwise) in
the
power
level.
5.
Rotate
the front panel knob rapidly
one quarter turn
in either direction. This should
cause a
large
change
in
power
level.
6.
If
a
keyboard has
a
problem, disassemble the front panel (refer to
FRONT PANEL REPAIR
PRO¬
CEDURES), and refer to either the A3 processor troubleshooting or the A5 and A7 keyboard
troubleshooting.
FRONT PANEL CONNECTORS
1.
Examine
all
connectors for contamination
or deformation,
HP 8340B/41B
Front Panel Overall Assembly-Level Troubleshooting G-7