Anritsu 682XXB - Manual (Page 215)

682XXB/683XXB MM 5-49
Output Power Level Related Problems
(20 to 40 GHz)
682XXB/683XXB Models with SDM
Error 138 SDM Unit or Driver Failed
Description: Error 138 indicates a failure of the SDM, a failure of the
SDM bias regulator circuitry on the A14 SDM Driver PCB, or a failure
of the frequency band selection circuitry on the A12 Analog Instruction
PCB. The 682XXB/683XXB will not produce an RF output in the 20 to
40 GHz frequency range.
Step 1. Set up the 682XXB/683XXB as follows:
a. 682XXB Setup:
CW/SWEEP SELECT: Step
F1: 20.000 GHz
F2: 40.000 GHz
Number of Steps: 400
L1: +1.00 dBm
683XXB Setup:
CW/SWEEP SELECT: Analog
F1: 20.000 GHz
F2: 40.000 GHz
Sweep Time: 0.100 Sec
L1: +1.00 dBm
Step 2. Connect the X input of an oscilloscope to the 682XXB/
683XXB rear panel
HORIZ OUT connector.
Step 3. Using the oscilloscope, check for a +8 volts SDM bias voltage
at A14TP2 throughout the full sweep.
G If the SDM bias voltage is correct, replace the SDM.
G If the SDM bias voltage is not correct, go to step 4.
Step 4. Replace the A14 PCB and run self-test again.
G If error 138 is not displayed, the problem is cleared.
G If error 138 is still displayed, go to step 5.
Step 5. Replace the A12 PCB and run self-test again.
G If error 138 is not displayed, the problem is cleared.
G If error 138 is still displayed, contact your local ANRITSU
service center for assistance.
Table 5-22. Error Messages 138, 139, 140, and 141 (1 of 2)
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