Anritsu 682XXB - Manual (Page 193)

682XXB/683XXB MM 5-27
+24VH Supply Problems
This supply provides +24 volts for the YIG-tuned oscillator heater, the
V/GHz circuit on the A12 PCB, and the coarse, fine, and YIG loop
circuits. When the 682XXB/683XXB is switched to
OPERATE , it also
takes over the function of the 24VS supply and supplies +24 volts to
the 100 MHz reference oscillator oven heater, the front panel LINE
switch circuitry, and the optional 10 MHz high stability time base oven
heater.
Step 10. Perform the following procedure to isolate malfunctions to
the +24VH supply and outlying load circuits.
a. Place the LINE switch to STANDBY .
b. Replace the A15 PCB assembly.
c. Place the LINE switch to OPERATE and measure the
+24VH voltage per Table 5-7.
G If the voltage is correct, the problem is cleared.
G If the voltage is incorrect, go to step d.
d. Place the LINE switch to STANDBY .
e. Remove the A4, A5, A7, and A12 PCBs and the YIG-
tuned oscillator assembly.
f. Place the LINE switch to OPERATE and measure the
+24VH voltage.
G If the voltage is correct, go to step g.
G If the voltage is still incorrect, contact your local
ANRITSU service center for assistance.
g. Place the LINE switch to STANDBY , then install one of
the removed PCBs or the YIG-tuned oscillator assembly.
h. Place the LINE switch to OPERATE and measure the
+24VH voltage.
i. Continue steps g and h until the faulty PCB/assembly is
located.
Table 5-6. Error Messages 105 and 106 (9 of 10)
TROUBLESHOOTING
TROUBLESHOOTING TABLES