Lexmark CS748de, Service Manual

Page: 192 / 504

3-14
Service Manual
5026
Go Back
Previous
Next
Hardware Tests
Panel Test
This test verifies the operator panel LCD function.
To run the Panel Test:
1. Select
HARDWARE TESTS
from the Diagnostics Menu.
2. Select
Panel Test
.
Note:
For C748x, the panel test continually executes. Each pixel is activated at the darkest level to the
lightest level, and then the backlight illuminates and turns off. This is repeated continuously.
Note:
For C746x, the operator panel display cycles through red, green, blue, white, and black.
3.
Press to cancel the test at any point.
Button Test
This test verifies the operator panel button function.
To run the Button Test:
1.
Navigate to
Diagnostics Menu > HARDWARE TESTS > Button Test
.
2.
C746x and C748x models have different button tests.
•
For C746x, follow the instruction on the operator panel display on which button to press.
•
For C748x, a keypad displays on the operator panel. Press each physical button one at a time and
observe if its corresponding button on the display lights up.
3. Press or touch
Back
to end the test.
DRAM Test
This test checks the validity of DRAM, both standard and optional. The test writes patterns of data to DRAM to
verify that each bit in memory can be set and read correctly.
To run the DRAM Test, navigate to
Diagnostics Menu> HATDWARE TEST > DRAM Test
. The power indicator
blinks
indicating the test is in progress.
Note:
If you need to exit the test before it is complete, turn off the printer.
P:###### represents the number of times the memory test has passed and finished successfully. Initially,
000000 displays with the maximum pass count being 99,999.
F:##### represents the number of times the memory test has failed and finished with errors. Initially, 00000
displays with the maximum fail count being 99,999.
Once the maximum pass count or fail count is reached, the test is stopped, the power indicator turns on solid,
and the final results appear. If the test fails, SDRAM Error appears for approximately three seconds and the
failure count increases by 1.
Serial 1 Wrap
The Serial 1 Wrap Test is used to check the operation of the serial port hardware using a wrap plug. Each serial
signal is tested.
DRAM Test 128M P:###### F:#####