Keysight Technologies N5290/1A PNA Series Service Manual page 95

N5290/91A Troubleshooting
N5292A Test Controller Troubleshooting
4. On the test set head, check to see if the head LEDs are working correctly
(LEDs illuminated red). If yes, run mm Mode Operations Check. Refer to
Chapter 3
Check" on page
5. If a millimeter-wave module (head) is not powered on (LEDs illuminated
red), power down the test set, and move the head to another port to
isolate the faulty port or head. Refer to
6. If the head is still acting faulty, power down the test set and swap in a
known working head. If the swapped head does fix the problem, power
down the test set and, return the faulty head to the Keysight factory for
repair.
Else, proceed to
"Verifying the A1 power supply" on page
Verifying the A5 Test Set Motherboard (TSMB)
This section describes the process for verifying that the TSMB is distributing
the proper voltages and signals to the A1 power supply, A2 LO preamplifier
(LOPA), A3 LO distribution amplifier (LODA), A4 phase compensation PCA, and
to the front panel ports.
Overview of the TSMB Voltages and LED Behavior
Power down the N5292A test set, remove the covers, and visually verify the
LED behavior using the descriptions below. Refer to
— There are 4 identical power supply fault detection circuits, one for each
port. The inputs to the circuit are +4.4V, +6.4V, +9.2V, -9.2V and -7V, and
the output is the color of LED indicator.
— Green LED represents the tested power supplies are alive and healthy.
— Red LED means at least one of the 5 listed power supplies is bad.
— When Magenta LED is illuminated the FPGA has not enabled +4.4V, +6.4V
and +9.2V. Refer to
Keysight N5290/1A Service Guide
and to "The N5290/1A Millimeter Test System Preliminary
3-7.
"Verifying the A5 Test Set Motherboard (TSMB)"
Figure 4-2 on page
Figure 4-2 on page 4-10.
4-17.
Figure 4-2 on page
4-10.
and to
4-10.
4-9