Keysight Technologies X Series Service Manual page 56

Boot Up and Initialization Troubleshooting
Potential Problems During Boot Process
Figure 2-3 A7 Midplane Board +5.1V LED
All DC power supplies come from the A6 Power Supply assembly. However, the most convenient
measurement location for all the DC supplies is the A7 Midplane. All power supply LED's are
accessible once the instrument cover has been removed.
Is the +5.1SB LED on the A7 Midplane board on?
If yes:
If no:
Before replacing the power supply, verify the midplane and motherboard interconnects are
mechanically secure.
56
After verifying that the connections from the front panel Standby LED back
to the A4 CPU board are not at fault, replace the A4 CPU board.
Replace the A6 Power Supply assembly.
Keysight N9010A EXA Service Guide