Power-On Self Test (Post) - Lexmark 248X-200 series Service Manual

24XX-200

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, and 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, and 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.