Dell Precision 400 Service Manual (.pdf) - Page 26

System Board The subsections that follow provide service-related information about the system board and components. The same system board is used in the midsize and mini tower computers. microphone jack line-out jack line-in jack riser board connector (RISER) USB connectors (2) NIC connector serial port 2 connector CD-ROM drive audio interface connector (CD-IN) mouse/keyboard connectors (stacked) secondary SEC cartridge (SLOT1_SEC) configuration jumpers parallel/serial port 1 connectors (stacked) processor fan connector (FAN) battery socket (BATTERY) DIMM sockets (4) main power input connector (POWER1) primary SEC cartridge (SLOT1_PRI) 3.3-V power input connector (POWER2) primary EIDE interface connector (IDE1) (pin-1 corner) secondary EIDE interface connector (IDE2) (pin-1 corner) front of computer diskette/tape drive interface connector control panel (DSKT) (pin-1 corner) connector (PANEL) Figure 1-11. System Board Components Main Memory The four DIMM sockets on the system board can accommodate combinations of 16-, 32-, 64-, and 128-MB DIMMs up to a total memory capacity of 512 MB. The computer is shipped with high-speed (60-ns) EDO DIMMs that provide ECC functionality when used with the Intel 82440FX PCIset. EDO ECC DIMMs can be mixed, as follows: • There is no requirement that one socket be filled before the other, and empty sockets can be left between installed DIMMs. Dell recommends populating the sockets in order from A to D. • DIMM sockets do not have to contain DIMMs of the same size. DIMMs may be installed in any order. See "DIMMs" in Chapter 4 or Chapter 5 for information on removing and replacing DIMMs. 1-14 Dell WorkStation 400 Systems Service Manual