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16900A, 16902A, and 16903A Service Guide
8
Theory of Operation
enumerating plug- and- play (PnP) devices in the system and
doing a "power on self test" (POST). All of the CPU
(motherboard) RAM is checked during POST- - however, subtle
memory problems may not be detected by this simple test.
If any hardware that the BIOS detects is malfunctioning at a
fundamental level, then the BIOS reports an error to the
display (if available) If things are OK control is turned over
to the operating system.
On units with front panels, the BIOS startup screen will be
displayed on the LCD panel. On faceless frames, the BIOS
startup screen will display itself out the rear VGA connector
to an attached monitor.
During startup, the Agilent logo is displayed by the system
BIOS, then a few other messages, and finally the preliminary
Windows XP startup screens.
During the first phase of the Windows startup, the kernel is
loaded along with various system drivers. Prior to the video
drivers loading, video is only displayed to the same video
device as the BIOS startup screen. Once the video drivers
load, the resolution will switch and eventually a logon screen
will be presented. The logon screen will appear on
whichever video adapter (LCD or external VGA) was
displaying the Windows desktop when the system was last
shut down.
It is possible (on frames with front panels) to get a blue
rectangle with an Agilent logo in it that says the current
display is not active. In this situation, you can press and
hold the "Touch Off" button on the front panel to switch to
the other display. At any time either the LCD panel or the
external monitor will have the Windows desktop displayed to
it. It is also possible, but not typical, for the Windows
desktop to be stretched across both the LCD and external
monitor. The "Touch Off" front panel button can be pressed
and held to force the desktop to use either the LCD or
external monitor exclusively.
By the time Windows has presented the Windows logon
screen to the user, two critical pieces of Agilent- specific
software should already be running:
•
Logic analyzer device drivers
•
Logic analyzer service
The remaining critical piece of Agilent software (the GUI
application itself) does not run until a user has logged onto
the machine and started the application by clicking on the
Summary of Contents for 16900A
Page 1: ...Agilent Technologies Agilent 16900A 16902A and 16903A Logic Analysis System Service Guide...
Page 6: ...6 16900A 16902A and 16903A Service Guide...
Page 14: ...14 16900A 16902A and 16903A Service Guide 1 General Information...
Page 18: ...18 16900A 16902A and 16903A Service Guide 2 Preparing for Use...
Page 22: ...22 16900A 16902A and 16903A Service Guide 3 Testing Performance...
Page 86: ...86 16900A 16902A and 16903A Service Guide 6 Replacing Assemblies...
Page 102: ...102 16900A 16902A and 16903A Service Guide 7 Replaceable Parts...
