682XXB/683XXB MM 5-49Output 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.
If the SDM bias voltage is correct, replace the SDM.
If the SDM bias voltage is not correct, go to step 4.
Step 4. Replace the A14 PCB and run self-test again.
If error 138 is not displayed, the problem is cleared.
If error 138 is still displayed, go to step 5.
Step 5. Replace the A12 PCB and run self-test again.
If error 138 is not displayed, the problem is cleared.
If error 138 is still displayed, contact your local ANRITSU
service center for assistance.
Table5-22. ErrorMessages 138, 139, 140, and 141 (1 of 2)
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