5-40 682XXB/683XXB MM
If the RF signal is correct in both frequency and ampli-
tude throughout the full sweep, go to step 8.
If there is no RF signal for all or part of the sweep or if
the amplitude of the RF signal is low,go to step 5.
Step 5. Connect the X input of an oscilloscope to the 682XXB/
683XXB rear panel HORIZ OUT connector.
Step 6. Using the oscilloscope, check for a –0.2 to –3.5 volt YIG
tuning ramp at A13TP10.
If the ramp signal is correct, go to step 7.
If the ramp signal is incorrect or not present, replace the
A13 PCB.
Step 7. Using the oscilloscope, check for the YIG bias voltages at the
test points shown in Table5-19.
If the YIG bias voltages are correct, replace the YIG-
tuned oscillator assembly.
If the YIG bias voltages are incorrect, replace the A13
PCB.
Step 8. Run self-test again.
If no error message is displayed, the problem is cleared.
If any of the error messages, listed above, are displayed,
contact your local ANRITSU service center for assistance.
Table5-18. ErrorMessages 124, 125, and 126 (2 of 2)
TROUBLESHOOTING
TROUBLESHOOTING TABLES
Test Point YIG-tuned Oscillator Bias Voltages
2 to 8.4 GHz 8.4 to 20 GHz
A13TP3 +6V +6V
A13TP5 0V +8V
A13TP6 –5V –5V
A13TP7 +8V 0V
Table5-19. YIG-tunedOscillator Bias Voltages