IBM 86624RY Maintenance Manual - Page 263

28 VRM 5 connector (J17) 29 VRM 5 error LED (CR7) 3 VRM 4 connector (J16) 31 VRM 4 error LED (CR2) 32 Reserved (J11) 33 VRM 3 connector (J14) 34 VRM 3 error LED (CR3) 35 VRM 2 connector (J13) 36 VRM 2 error LED (CR6) 37 VRM 1 connector (J12) 38 VRM 1 error LED (CR5) 39 - 42 Microprocessor core-frequency-selection jumper block (J31-J28) 43 Reserved (J27) 44 Reserved (J25) 45 Reserved (J26) 46 Reserved (J19) 47 Reset system jumper block (J34) Processor board jumpers Table 14 on page 256 contains the names and descriptions of the jumper blocks located on the processor board. Table 15 on page 256 shows the microprocessor core-frequency-selection jumper settings. The highlighted numbers in the table refer to the highlighted numbers in the illustration in "Processor board component locations" on page 254. Notes 1. Turn off the server, and disconnect the power cords before moving any jumpers. 2. Be sure the microprocessor bus-to-core fraction is set correctly. For example, if you have a 400 MHz2 microprocessor installed and the system bus speed is 100 MHz (the default), jumpers J28-J31 are set to a bus-to-core fraction of 4 (400/100). See Table 15 on page 256. Attention If the microprocessor bus-to-core fraction is incorrect, system board components will overheat and component damage might occur. Be sure that the microprocessor core frequency selection is properly set. 2 400 MHz denotes internal clock speed of the microprocessor only; other factors also affect application performance. Netfinity 5500 M20 - Type 8662 255