Keysight Technologies N5222B, Service Manual

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4-8 Keysight N5290/1A Service Guide
N5290/91A Troubleshooting
N5292A Test Controller Troubleshooting
4-
No DC Power for Millimeter-wave Modules
This section isolates a faulty millimeter-wave module or a faulty N5292A test
set.
This section contains the following procedures:
— “Procedure for identifying a faulty millimeter head:”
— “Verifying the A5 Test Set Motherboard (TSMB)”
— “Verifying the A1 power supply”
— “Verifying the A2 LOPA, A3 LODA, and A4 Phase Compensation Boards”
— “Head Stability Check”
— “Front Panel Active LED”
— “RF OUT Failures”
— “LO Out Failure”
— “REF IF or Test IF”
— “Test Set Diagrams and Graphics”
Equipment required:
— Power supply fixture – Refer to Figure 3-10 on page 3-19
— PNA 10 MHz to 26.5 GHz (minimum)
— Millimeter-wave head(s)
Procedure for identifying a faulty millimeter head:
1. Power down the test set and remove the top and bottom covers. Refer to
Chapter 7 and “Removing the Outer Cover” on page 7-8 .
2. Connect the suspect millimeter-wave head to the test set.
3. Power up the N5292A test set.
A photo sensor is mounted behind the integrated (SV) cable connector for
each port. There is a special jack screw which tightens the SV cable to the
N5292A Test Set. When the jack screw is fully tightened, the head is
securely connected to the test set and enables the TSMB to receive a
digital signal to indicate that it is safe to turn on the critical power
supplies, 4.4V, +6.4V and +9.2V. These supplies power many
expensive power-sensitive components in the head, which it is important
to protect from hot plug or hot unplug.