Agilent Technologies XX3625 Service Manual page 89

Time Audible Indicators
4 HDD clicking*
5 HDD clicking*
6 HDD clicking*
7 Attenuators click as
solenoids are preset
to known states
8 Attenuators click to
their operating states
(second interval,
indicates scope
running)
* Later model hard disk drives are much quieter than earlier models.
The clicking can only be heard with the instrument sleeve removed and in close proximity to the hard disk drive.
Visible Indicators
PC Power-On Self Test
(POST) memory test message
on external monitor.
System board configuration
appears on external monitor
and internal display.
The Infiniium display appears
on the internal and external
displays.
Front panel LEDs change to a
normal operating pattern.
Both screens go blank
momentarily.
Oscilloscope display comes
up on both the external
monitor and the scope's front
panel display.
Description
The HDD begins clicking* as it is
accessed by the system. The
external SVGA monitor shows the
POST messages. These messages
show the memory test.
The HDD continues clicking* as the
instrument loads the oscilloscope
application. The flat panel LCD
backlight comes on and the display
shows the system board
configuration. This is an indication
that the motherboard and SVGA
display board are functioning
correctly.
The HDD continues clicking.*
The attenuators click. This is louder
than the HDD clicking and comes
from the front of the instrument. The
front panel LEDs change to a normal
operating pattern. For example, the
Trigger LEDs show only one trigger
mode, such as Edge, and one trigger
coupling, such as dc.
The attenuators click a second time.
The oscilloscope display backlight
comes on, and the display appears
on both the external monitor and the
scope's front panel display. The
oscilloscope is running.
Chapter 5: Troubleshooting
No Display Trouble Isolation
Troubleshooting
If there is no display on the
external monitor, either the
motherboard A4 (including CPU
or RAM), the SVGA display
board, cabling, or external VGA
monitor are suspect. Check the
cabling and VGA monitor first.
Next, use a POST (Power-On Self
Test) card to help isolate the no-
display problem. Install the POST
card in an ISA slot and apply
power to the instrument. The
POST card displays the
respective codes as the power-
on self tests are completed. See
the "POST Code Listing" in this
chapter for codes and
descriptions. Replace the
motherboard, CPU, or RAM as
indicated from the POST code
listing.
If the attenuators click a second
time but the display does not
come up, try the front panel keys
to see whether they respond. If
so, there is a display problem. If
the external monitor shows the
screen but the oscilloscope does
not, the problem may be with
cabling, the backlight inverter
board A3 not supplying +900 V
and +12 V, the flat-panel display
A2, or the SVGA display board
A5. See the sections "To check
the backlight inverter voltages"
and "To check the SVGA display
board video signals."