System Start-Up And Post; Power On Self Test (Post) - Xerox Phaser 4500 Service Manual

System Start-Up and POST

Power On Self Test (POST)

Phaser 4500/4510 Service Manual
The following tests are performed when the printer is powered on, after the
boot loader runs, and before the operating system is loaded and initialized.
POST diagnostics are intended to provide a quick means of isolating a
defective subsystem associated with the image processor board and SDRAM.
POST returns control to the boot loader and the operating system is loaded.
The operating system then loads the imaging processing software. If POST
detected any soft errors, a message is printed in a gray box on the start page.
If POST detects any hard errors, both the control panel and health LED blink
the error code pattern, see "LED Blink Patterns" on page 3-16.
POST Startup indications
At power-on the hardware default is to turn on the IP board 'health' LED.
The image processor board 'health' LED is turned off.
The control panel display is reset (addressable area becomes "gray").
The Red LED turns on.
The backlight is turned on (normal intensity), with nominal contrast
display for 1/4 second.
The control panel display area is turned on, dark black for 1/4 second.
The control panel display is cleared for 1/4 second.
The backlight is turned off with nominal intensity for 1/4 second.
The POST Vn.nn message appears, and tests are quickly executed.
If any tests fail, the control panel screen freezes with the name of the test
displayed and the line posted is "Call Customer Service".
After the POST tests have finished running, the Xerox 'splash screen' is
posted to the control panel and PostScript begins initialization.
Error Messages and Codes
3-15