Agilent Technologies 66332A

Troubleshooting - 3
35
Pro
g
ram the out
p
ut
volta
g
e and current to
the full scale value and
the OV to 1/2.
OV
_p
ro
g
~+2V
@
R350
?
U306B-8
~+2V
?
A
2 Interface Board o
r
cable W7 defective
Check R350, C335 and
U306B
Yes
No
No
U306B-7
~+4V
?
Yes
Check R349, R351,
R356, C336 and U306
No
U306B-2,
OV
_
DETECT*,
Low?
Yes
Check U306B
No
OV_SCR* pulse @
R438 low 5us
?
Yes
Check Q318B, R441,
A
2 Interface Board
No
Q318D Collector
pulses high 5us
?
Check Q318A, B and D
and associated circuits
Yes
No
Check A1CR342
Yes
Reset the OV
(
Shift,
Prot Clr
)
and observe
the OV
_
SCR* si
g
nal.
Each time OV is reset
the unit will
g
enerate
another OV si
g
nal. The
OV
p
ulse
(
OV
_
SCR*
)
is a
pp
roximatel
y
5us
lon
g
.
See note
Figure 3-1 Sheet 11. Unit Does Not OV