Potential Problems During Boot Process; Yellow Standby Led Does Not Illuminate - Agilent Technologies N9039A Service Manual

Potential Problems During Boot Process

This section describes potential problems that may occur if there is an internal
hardware issue that prohibits the N9039A from completing a full boot up to the RF
Preselector application.

Yellow Standby LED Does Not Illuminate

Control of the yellow front panel Standby LED comes from the A4 Processor
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 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.
2. Remove the AC power cord and then remove the instrument cover. Refer to the
Chapter 7, "Assembly Replacement Procedures," on page 161
3. Referring to
board is on (green).
Figure 2-2 A7 Midplane Board +5.1V Standby LED
Chapter 2
Figure 2-2, verify the +5.1V Standby LED on the A7 Midplane

Potential Problems During Boot Process

in this manual.
Troubleshooting
37