HP 8340b User Manual

All
Numeric
Displays
are
Blank
1.
Connect
the
oscilloscope to
the
CLK
test
point
(A2TP6),
and
set
it
to
0.5 ns/div,
1
V/div (0V
=
center
screen).
The
waveform
displayed
should be
low for
2.5
to
3.0
(is,
with levels
between
+2V
and approximately
—
2.5V.
If
this
signal
is
not
present,
the
trouble
is
the
NUM
CLK
on
the
A2
assembly.
2.
Troubleshoot
the
A2
assembly.
Entry
Display
Is
Blank
1.
Connect oscilloscope
to
ALPHA
CLK
(A2TP2),
and
set
it
to
0.5
^S/div,
1V/div
(OV=Center
screen).
The
waveform
displayed
should be TTL
low-going
pulses,
0.3
nS
wide,
with
a
period
of
1.4
iis.
If
this signal
is
not
present,
the
trouble
is
the
alpha
display
clock
control
in
the
A3
assembly.
2.
Connect
the
oscilloscope
to
DATA
(A2TP1),
set
as
in
step
1.
The
waveform
display
should
indi¬
cated
both
high
and
low
signal
levels
approximately 1.4
(is wide.
If
the
DATA
signal
is
always
low,
all
LEDs
in
the
ENTRY
display will
be
off.
If
this
signal
is
not
present,
the
trouble
is
the
A3
assembly
alpha
display
shift
register.
t
3.
Troubleshoot
the
A2
assembly.
The
Same
Segment(s)
is
Missing
In
Each
Numeric
Digit
1.
Troubleshoot
the
A2
assembly.
The
Same
Column
is
Missing
in
Each
ENTRY DISPLAY
Character
1.
Troubleshoot
the
A2
assembly.
One
Entire
Numeric
Display
is
Blank
1.
Troubleshoot
the
A2
assembly.
The
Display
Goes
into
Self
Test
When the
Instrument
is
Turned
ON
and
Does
Not
Respond to
Normal
Instrument Functions
1.
The
trouble
is
the
A3
instrument
bus
interface.
HP
8340B/41B
A3
Display
Processor
Assembly-Level Troubleshooting
G-9

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English