HP 8340b User Manual

Sometimes
Keystrokes
are
Missed
by
the
Instrument
1.
The
problem
is
in
the
A6
key down
timer.
The
instrument
Responds
Only
to Keystrokes and/or
the
Front
Panel
Knob
when
in
a
Swept
Mode
1.
The problem
is in
the
A6
SRQ
buffer.
No
Response
when
the Front
Panel
Knob
is
Turned
1.
Press
a
function
key
and verify that the
ENTRY
ON
LED
lights.
If
this
LED
does
not
light,
the
trouble
is
the
annunciator latches.
2.
If
the
ENTRY
ON
LED
is
on,
probe
CLK
(A6TP1)
with
an
oscilloscope
set
to
5
ms/Div.
You
should
see
low
going
pulses
as you
turn
the
front
panel
knob,
and
the
pulse
width
should
vary
with
the
speed
of
rotation.
If
CLK
is
bad,
the
trouble
is
in
the
RPG
(rotary
pulse
generator) or
the
RPG
counters/data
buffers.
3.
Probe
HI
RPG
SRQ (A6TP8).
You
should
find
high
going
pulses
that
vary
in
width
depending
on
the
response
time
of the
instrument
processor
to
an SRQ.
These pulses
should be
between
100
US
and
25
ms.
If
HI
RPG
SRQ
is
correct,
the
trouble
is
the
SRQ buffer
or
the
RPG
counters/data
buffers.
If
HI
RPG
SRQ
is
not
correct,
the trouble
is
the
RPG
count
window
timer.
Turning the
RPG
Causes
Either
Very
Small
or Very
Large
Changes
in
the
Active Function
in
the
ENTRY DISPLAY
1.
The
problem
is in
the
A6
RPG
count window
timer.
The
Instrument
Does
Not
Preset
when
[INSTR PRESET]
is
Pressed
1.
The
problem
Is
in
the
A6
instrument
preset buffer.
G-12
A6
Keyboard Interface
Assembly-Level
Troubleshooting
HP
8340B/41B

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English