Self Tests; A60 Processor Self Test Leds; Shift M4 - HP 8340B Manual

SELF TESTS
At
power
on and at instrument preset, self test performs diagnostic checks on some of the instrument
circuitry.
The
tests performed are
the
SHIFT M4
tests
0
through
8, and 10
through
13
(described under
SHIFT
M4).
Figure F-2 shows the instrument self test flow chart.
How to Check the Results of Self Test
You can check the results of instrument self test
in 3
ways:
•
On the
INSTR CHECK LEDs
I
and
II
•
Using the A60 Processor Self Test LEDs
•
Using the diagnostic
SHIFT M4
NOTE: The most accurate failure
indication is
given by the A60 processor self test LEDs.
A
failure
can occur that invalidates the indication of the
INSTR CHECK
LEDs and
SHIFT
M4.
Instrument CHECK LEDs
I
and
II
The INSTR CHECK
LEDs I
and
II
are the easiest failure indicators to check because they are located
on the front panel, adjacent to the [INSTR PRESET]
key.
Procedure
1.
Switch on
power or press
[INSTR
PRESET].
Both INSTR CHECK LEDs turn on.
LED I turns off when the processor, memory, and peripheral interface timer (on
the
A60 assembly)
pass
self
test (SHIFT M4
tests
0
through
6,10,
and 11).
LED II turns off when the
I/O address bus, I/O
data
bus,
and marker RAM pass self test
(SHIFT M4
tests
9,12,
and
13).
If
no failure occurs, both LEDs
are
off after approximately
1
second.
If either LED remains on, check
the 16 LEDs on the A60 assembly. Remember that it is
possible
for
a
failure to
occur that causes both
INSTR CHECK LEDs
to
go
off
when
they shouldn't.
HP 8340B/41B
A60
Processor
Assembly-Level Troubleshooting F-15