Motherboard Assembly - Keysight 90000 X Series Service Manual

Chapter 7: Theory of Operation

Motherboard Assembly

Motherboard Assembly
The motherboard provides all system control and interface functions for the
oscilloscope. The motherboard contains a microprocessor, a hard disk drive
interface, ROM, RAM, keyboard and mouse interfaces, connections to the front
panel board, and serial interfaces.
Pressing the on/off button sends a signal to the motherboard. The motherboard
then signals the backplane assembly, which in turn sends a signal to tell the
bulk 12V power supply to turn on. When the power supply turns on, the
remaining power supplies are enabled and powered on. Then the main FPGA
on the backplane assembly gets self- configured from its PROM. Once it's
configured, the main FPGA asserts a signal to tell the motherboard to power
up and become fully functional.
The hard disk drive is a high- capacity, shock- resistant unit that stores the
oscilloscope operating system, the oscilloscope application, compliance
application information, calibration data, other data files, and drivers for the
boards and oscilloscope. The hard disk drive can also be used to store and
recall oscilloscope setups and waveforms.
Note that it is important for the hard disk drive image to match the motherboard.
If they do not match, the oscilloscope may not have the correct Windows software
drivers.
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