HP 8340B Manual page 126

10. Measure
and record the
voltages at:
A31P1
pin13(M1)
pin
28 (M2)
pin14(M3)
pin
29 (M4)
pin15(M5)
Compare the recorded voltages with the voltage levels provided in
Table
B-1
(use the
M
divide
number shown
in
the POWER dBm display to determine
which voltage levels to use
in
the table).
If
the voltages are correct, proceed with step
12.
If
any of the voltages
are
incorrect, proceed with
step
11.
11.
Remove the
A31
assembly and repeat
step 10.
If
the voltages
are
still
incorrect, the failure is due to
a
shorted or open trace on
the
A34 reference
loop
—
M/N
loop Motherboard or an
A59 digital
interface
assembly failure.
If
the voltages for the
M1
through
M5 inputs are
now correct, replace
A31.
12.
Measure
and record the voltages
at:
A31P1 pin
8(N1)
pin
23 (N2)
pin 10
(N3)
pin 25 (N4)
pin 9
(N5)
pin
24 (N6)
Compare
the recorded voltages with the voltage levels provided in Table
B-1
(use the
N
divide
number shown in
the
POWER dBm
display to
determine which voltage levels to use in
the table).
If
the voltages are correct, proceed with step 14.
If
any of the voltages
are
incorrect, proceed with
step
13.
13.
Remove the
A31
assembly and repeat step
12.
If
the voltages
are
still
incorrect, the failure is
due to
a
shorted or
open trace on the A34 reference
loop
—
M/N loop motherboard or an A59 digital
interface assembly failure.
If
the voltages for the
M1
through
M5
inputs are now correct, replace
A31.
B-24 M/N
Loop
Assembly-Level Troubleshooting
HP 8340B/41B