Dram Memory Test - Lexmark C720 Service Manual

5024-001
To run the ROM memory test:
1. Select ROM Memory Test from the menu.
P and F represent the same numbers for DRAM. The power
indicator blinks indicating the test is in process. The test runs
continuously.
2. Press Return/Stop to exit the test.
Each time the test finishes, the screen updates with the result. If
the test passes, the pass count increases by 1, however if the
test fails, one of the following messages displays for
approximately 3 seconds:
•
ROM checksum error
•
ROM burst read error
Once the maximum pass count or fail count is reached, the test
stops with the power indicator On solid. The final results display
on the screen.

DRAM Memory Test

The purpose of this test is to check the validity of SDRAM, both
standard and optional. The test writes patterns of data to SDRAM to
verify that each bit in memory can be set and read correctly.
To run the SDRAM memory test:
1. Select SDRAM Memory Test from the menu.
The power indicator blinks indicating the test is in progress.
2. Press Return/Stop to exit the test.
P:###### represents the number of times the memory test has
passed and finished successfully. Initially 000000 displays with
the maximum pass count being 999,999.
F:##### represents the time 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 is turned On solid, and the final
results display. If the test fails, the message DRAM error,
displays for approximately three seconds and the fail count
increases by 1.
Diagnostic Aids
3-11