Power-On Self Test (Post) - Lexmark Forms Printer 2400 Service Manual

24xx

Power-On Self Test (POST)

The following tests are automatically performed when the printer is
turned on.
•
LEDs Test - Checks operation of LEDs on the operator panel.
The LEDs turn on and off after the printer is turned on, then all
LEDs turn on for a few seconds.
•
RAM Test - Checks that the CPU can write/read the RAM.
•
Font ROM/Microcode Sum Test - Checks that the ROM data is
correct.
•
Timer/Interrupt Controller Test - Checks that this function works.
•
NVRAM Test - Checks that the NVRAM data is correct.
•
Switch Scan Test - Checks the buttons on operator panel.
•
Carrier Initialization - Carrier moves to the left to activate the
home position sensor, then moves to the first print position.
•
Feed Initialization - Form feed motor rotates forward and then
backward.
If any errors occur during the POST tests, a combination of blinking
LEDs indicates which test failed. See
3-2
Service Manual
"Start" on page 2-1.