HP 8340B Manual page 247

Controller Section
Overall Assembly-Level Troubleshooting
Because problems on either
the
A57 assembly or the A59 assembly can show up indirectly
in
other
areas of
instrument operation,
it is
particularly important that you begin A57 and ASS troubleshooting
in the overall instrument troubleshooting, located in
the service introduction of this manual.
The majority of controller functional group assembly level troubleshooting
is
associated
with the
A60
processor assembly. Consequently, some A57 and A59 diagnostics and troubleshooting are included
in
the
A60
information.
There are two
levels of diagnostics and troubleshooting for the controller group:
•
Self
Test
At power on and at instrument preset, self tests perform diagnostic checks
on
some controller
group circuitry. The tests performed are diagnostic routine
SHIFT M4
tests
0
through
13,
and 20.
Two
front panel
LEDs (CHECK I
and II) provide
a
visual indication of the self test results, and are
explained
in
the
AGO
assembly troubleshooting.
•
Assembly Isolation
Verify individual assembly
faults by removing
the assembly and observing instrument behavior.
Once
an
assembly
is
suspect,
its replacement verifies the cause of the problem.
Self tests, diagnostic tests, and assembly isolation procedures are described
in
each assembly
trou¬
bleshooting section.
y^^^^.
I
CAUTION
j
Before you
remove an assembly,
disconnect line
power
and wait several
minutes for the
A19
power-on safety indicator to go out.
HP 8340B/41B
Controller Section Overall Assembly-Level Troubleshooting F-9