Agilent Technologies 6612B, Руководство по обслуживанию, Страница: 29 / 74

Troubleshooting - 3
29
"C" From Sheet 3 or 6
Output and display
close to prog value
?
Calibrate Current
Yes
Unreg Annunciator
ON
?
No
CC_PROG OK?
Replace A2 Interface
board
No
IMON_H OK?
Yes
Troubleshoot R431
and U319A circuit
No
If output is OK and readback is
not, replace A2 Interface board.
If the display equals the output,
troubleshoot U324A/B circuit
circuits.
CC_PROG @ R336 is 0 to -4.8V
for 0 to full scale programmed
current, IMON_H @ U318A-7 is 0
to -4.8 volts for 0 to full scale output
current and IMON_L @ U319A-6 is
0 to -4.8 volts for 0 to 20mA output
current in the low current readback
range.
No
IMON_L OK?
Yes
OK below about
12mA but not
above?
No
Check Q302 circuit
Yes
Check U319A circuit
No
Yes
Go to "Output Current
Unregulated" Sheet 13, "I"
Yes
Figure 3-1 Sheet 7. Current Troubleshooting