Lexmark T620 Service Manual - Page 181

4069-5XX/7XX SDRAM 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 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 is turned on solid, and the final results display. If the test fails, the message SDRAM Error, displays for approximately three seconds and the failure count increases by 1. ROM Memory Test The ROM Memory Test is used to check the validity of the system board code and fonts. 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. Diagnostic Aids 3-15