Lexmark 25**-100, Service Manual

Page: 64 / 188

3-2
Service Manual
25XX-100, -110
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
“Start” on page 2-1 .