Installation guide

Troubleshooting
Troubleshooting Assembly Level Problems
1-64
2003 VBLO Test
• Replace the A14 Extended Frequency Output (Option 506).
2004 Marble Test
• Measure the Q signal from the A10 I/Q Multiplexer (Option 506).
a. Disconnect the cable at J9 of the A19 Daughterboard and connect it to a DVM.
b. Set the CW frequency to 6 GHz.
c. Turn on the I/Q modulation and adjust the Q offset with the following keys:
— I/Q hardkey
— I/Q On
— I/Q Adjustments
— I/Q Adjustments On
—Q Offset
d. Rotate the RPG and observe the DVM.
The voltage should vary from approximately +0.30 Vdc for an offset of 50% to approximately -0.20 Vdc
for an offset of 50%.
— If the signal is bad, check the signal at J6 of the A10 I/Q Multiplexer (Option 506).
— If the signal is bad at J6, refer to troubleshooting the A10 I/Q Multiplexer (Option 506).
— If the signal is good at J6, change the cable.
• Measure the I signal from the A10 I/Q Multiplexer (Option 506).
a. Disconnect the cable at J8 of the A19 Daughterboard and connect it to a DVM.
b. Set the CW frequency to 6 GHz.
c. Turn on the I/Q modulation and adjust the I offset with the following keys:
— I/Q hardkey
— I/Q On
— I/Q Adjustments
— I/Q Adjustments On
— I Offset
d. Rotate the RPG and observe the DVM.
The voltage should vary from approximately +0.25 Vdc for an offset of 50% to approximately -0.25 Vdc
for an offset of 50%.
— If the signal is bad, check the signal at J5 of the A10 I/Q Multiplexer (Option 506).
— If the signal is bad at J5, refer to troubleshooting the A10 I/Q Multiplexer (Option 506).
— If the signal is good at J5, change the cable.