Toshiba Satellite Pro U300 Maintenance Manual - Page 159

Test Program for Field. 3.14 MEMORY2 Test To execute the Expansion Test select 11 from the Diagnostic Test Menu, press Enter and follow the directions on the screen. The MEMORY2 Test contains four subtests that test the computer's. Move the highlight bar to the subtest you want to execute and press Enter. NOTE: If NO is selected for Test Loop on the Test Parameter menu, the Test Status screen displays while the test is executing. When the test is complete the Memory Test menu displays. If YES is selected for Test Loop on the Test Parameter menu, the Test Status screen displays while the test is executing. Press Ctrl + break to return to the Memory Test menu Subtest 01 Subtest 02 Subtest 03 Subtest 04 All one/All zero test This subtest performs pseudorandom data read/write. The data consists of "all ones"/"all zero" patterns produced by pseudorandom sequence generator. The test checks address error. FFFFFFFFFFFFFFFF0000000000000000 0000000000000000FFFFFFFFFFFFFFFF Walking 1/Walking 0 test (Left) This subtest uses "running one"/"running zero" patterns. This test sequence allows also to checking system bus in maximum noise conditions. The following test sequence is written. 7FFF7FFF7FFF7FFF8000800080008000 BFFFBFFFBFFFBFFF4000400040004000 After all the memory being tested is filled with the pattern, it is read in descanting direction and compared with reference data. As the memory is read, the data is replaced with inverse test pattern. After all the memory is read and replaced with inverted pattern, it is read in descanting direction and compare with new reference data. As the memory is read, the data is replaced with next pattern, which is like first one shifted to right. Walking 1/Walking 0 test (Right) Tee test method is the same as Subtest2. However, the data to be used differs. 80008000800080007FFF7FFF7FFF7FFF 4000400040004000BFFFBFFFBFFFBFFF Walking 1/Walking 0 test (Left/ Right) Satellite U300 and Satellite Pro U300 Tests and Diagnostics Manual 55