Electronics Module - Xerox Phaser 8400 Service Manual

Electronics Module

The electronics module includes the main board, the power control board, and the
power supply. The electronics module is a Field Replaceable Unit (FRU) assembly.
Main Board
The main board performs the image processing functions. Communication ports on
the board receive the print job image data and convert it to drive signals for the
printhead. The main board also contains the mechanical process controller, which
commands the function of the power control board. The main board sends signals
through the power control board to the wave amp board, which amplifies the signal
that drives the jets on the printhead. The main board supports Non-Volatile RAM
(NVRAM), memory, the hard drive, input/output ports, and the configuration card.
NVRAM: The NVRAM memory device, located on the main board, stores Control
Panel defaults, network settings, calibration data, copy counts, usage profile data, and
the printer serial number, which is also referred to as the Engine Tracking
Number (ETN). When the electronics module is replaced, the NVRAM must be
transferred to the main board in the replacement electronics module.
Memory: For Phaser 8400 printers, the main board supports two PC 133 compatible
SO-DIMM SDRAM memory modules (128 to 256 MB). Phaser 8500/8550 printers
support SIMMs instead of DIMMs. Supported sizes are 128, 256, and 512 MB.
Printers ship with a minimum of 128 MB and support a maximum of 1024 MB
Hard Drive Support:
hard drive board. A separate power cable must plug into the power control board from
the hard drive board to provide signals and power for the hard drive board.
Input/Output Ports:
Ethernet (not supported on the B and BD printer configurations), Parallel, and USB
2.0 external I/O interfaces. For the 8500/8550, the main board provides support for
Ethernet (all printer configurations), and USB 2.0 external I/O interfaces. The 8500/
8550 configurations do not include parallel interfaces.
Configuration Card
The configuration card is a thumbnail-sized device that plugs into the side of the
electronics module. This device stores printer information and interacts with the
printer's NVRAM chip. The configuration card supports the transfer of printer model
and network configuration information from a failed printer to a replacement printer.
When replacing the electronics module, you must transfer the configuration card to
the replacement electronics module.
Information stored on the configuration card includes the feature value, ethernet
address, and personality parameters. The card reads a combination of feature values
and the printer hardware capabilities; this will determine the printer model
configuration.You can migrate the configuration card from one printer to another to
Theory of Operation
A hard drive IDE cable plugs into the main board from the
In the Phaser 8400, the main board provides support for
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