Power On Self Test (Post) - Xerox Phaser 6300 Service Manual

Power On Self Test (POST)

POST diagnostics provide a quick means of isolating a defective subsystem
associated with the Image Processor Board and SDRAM. There are two kinds of
POST faults: soft and hard. A soft fault is any fault that allows the operating system to
initialize. Soft faults do not stop printer operation and are reported on the Startup page
after the system is running. A hard fault prevents the operating system from
initializing stopping further printer operation. Hard faults are indicated with blinking
LEDs and the failed test appearing on the display.
The following tests execute when the printer is powered on after the Boot Loader
runs, and before the operating system is loaded and initialized. Bypass POST by
pressing the OK button at power on until the splash screen displays.
POST Test Descriptions
Fault
Test Code
SDRAM 1
Control Panel
Extended 7
Memory
EEPROM 10
Ethernet 11
CPU 12
Interrupts
USB 13
Real-Time 14
Clock
RAM DIMM 15
Min. RAM 16
Max. RAM 17
IDE Disk 20
Engine 22
Command
General Troubleshooting
Fault
Type Description
Hard This test fails if the boot loader finds no or faulty RAM (Run
prior to POST.). The boot loader displays "RAM ERROR" and
blinks the Health and Control Panel LEDs.
Hard This test checks the Control Panel connection and firmware.
A fault is indicated on the Health LED.
This test does a write compare test to each 32-bit word in
extended memory.
Hard This test checks addressing of the EEPROM.
Soft This test checks the ethernet core.
Hard This test checks that each interrupt to the CPU is functioning.
Soft This test checks that the USB core is functioning properly.
Soft The real-time clock is tested.
Soft This test checks RAM compatibility.
Hard Checks that there is at least 128 Mbytes installed. Control
Panel displays "Install More RAM" on failure.
Soft Checks that there is no more than 1 GB installed.
Soft Checks for a hard drive, then checks the disk controller core.
Hard Checks communications between the Engine Control and
Image Processor boards.
4-3