Post Faults; Led Blink Patterns - Xerox Phaser 4500 Service Manual

Error Messages and Codes

POST Faults

LED Blink Patterns

3-16
There are two kinds of faults: soft and hard.
A soft fault is any fault that is discovered by POST, but does not prevent the
operating system from initializing and becoming available as a tool for
troubleshooting. These POST faults do not stop execution and are reported
on the Start Page in a gray box after the system is running.
A hard fault is any fault discovered by POST that prevents the operating
system from initializing successfully. A hard fault prevents the system from
further execution and is halted with blinking LEDs (control panel and health
LED). The test name of the test that failed is displayed on the control panel.
Fault Reporting Devices
There are four fault presentation devices.
All soft faults are printed on the StartPage.
For hard faults:
The health LED flashes according to the fault code.
The control panel LED flashes in unison with the health LED.
The last posted message to the graphic control panel is present.
For faults identified as hard faults, the POST firmware causes the PS health
LED to blink in a particular pattern to identify the fault. There are short and
long blinks. A long blink is worth 5 and a short blink is worth 1. If a fault blink
pattern is flashed as long, long, short, short, this is fault code 5+5+1+1=12,
which indicates a failure in the CPU interrupt test. See "POST Diagnostic Test
Descriptions" on page 3-17.
The exception to the above pattern is a RAM test error. The RAM tests have a
special blink pattern and the control panel displays "RAM Error". During power
up the control panel LED is on. If the RAM tests fail, the image processor
board health LED is turned off, and the control panel LED is red. At 1/2-
second intervals, the health LED and the control panel LED toggle
continuously.
Phaser 4500/4510 Service Manual