Display/Power Supply Section - Agilent Technologies 8564EC Service Manual

General Troubleshooting
Block Diagram Description
Display ASM Much of the miscellaneous digital control is performed
by A2U100. U100 functions as the display ASM (algorithmic state
machine) and character ROM. It also converts the 16-bit CPU data bus
to an 8-bit data bus for the rest of the spectrum analyzer.

Display/Power Supply Section

A6 Power Supply
The A6 power supply is a switching supply operating at 40 kHz
The speed of the spectrum analyzer fan is variable. A thermistor on A6
senses the temperature and adjusts the fan speed accordingly. This
allows the spectrum analyzer to run quietly in most room-temperature
environments and faster (louder) only when necessary.
A17 LCD Display Driver
The display is an LCD color flat panel screen with 640 X 480 VGA
resolution. A connector for an external VGA is available at the rear
panel. The A17A1 backlight supply provides the high voltage to supply
the two backlights in the LCD display. The LCD display is not
adjustable.
The display driver board consists of the Hitatchi 7707 processor, an
Actel FPGA, DRAM, SRAM, a filter circuit, and a video DAC. This
board monitors the 8560 EC-series controller board, copies display
instructions to local memory, creates a bitmap from the data, and
generates the signals needed to drive the LCD and a VGA monitor. The
video DAC converts the digital color information from the LCD to
analog; these analog signals drive the RGB color lines on the VGA port
on the rear panel.
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