Potential Problems During Boot Process; Yellow Standby Led Does Not Illuminate - Keysight n9020a Service Manual

Boot Up and Initialization Troubleshooting

Potential Problems During Boot Process

Potential Problems During Boot Process

This section describes potential problems that may occur if there is an internal
hardware issue that prohibits the MXA from completing a full boot up to the
spectrum analyzer application.

Yellow Standby LED Does Not Illuminate

Control of the yellow front panel Standby LED comes from the A4 CPU board
assembly. This signal is routed through the A7 Midplane board and is then
buffered on the A8 Motherboard before being sent to the A1A2 Front Panel
Interface board through W1. Of course, the power for this all originates with
the A6 Power Supply Assembly. When the Standby LED does not come on it
could be due to any one of these assemblies. This procedure will help to
determine which one is the cause.
If the instrument turns on and operates properly but the yellow Standby LED
does not work then all that will need to be done is to trace where the control
signal for the LED is being lost using the routing information in the preceding
paragraph.
1. The Standby LED will only turn on when the instrument is connected to an
2. Remove the AC power cord and then remove the instrument cover. Refer
3. Refer to
Figure 2-3 A7 Midplane Board +5.1V LED
AC source that has a voltage level and frequency of that specified for the
instrument. Before proceeding verify that these requirements are being
met. Refer to the instrument rear panel for these requirements.
to the Chapter 14, "Assembly Replacement Procedures", on page 435
this manual.
Figure 2-3, verify the +5.1V standby LED on the A7 Midplane
board is on.
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