Apple Desktop Computer manual Removing the EMI Shield, Removing the Logic Board Assembly

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C H A P T E R 4

RAM Expansion

Removing the Logic Board Assembly

With the retaining screws removed and the cables positioned to the sides, the user can remove the logic board assembly by pulling upward on the handle, as shown in Figure 4-4.

Figure 4-4Removing the logic board assembly

IMPORTANT

While removing and reinstalling the logic board assembly, you should take care to align the door of the CD drive with the opening in the front of the case.

Removing the EMI Shield

Once the logic board assembly is free of the case, you can see the EMI shield, which covers the processor module. To gain access to the main RAM expansion slots, you must remove the EMI shield, as shown in Figure 4-5.

46The Expansion Slots

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Contents Apple iMac Computer Page Contents Devices and Ports RAM ExpansionSoftware RtasAppendix Abbreviations Index Rtas NV-RAMFigures and Tables Page Contents of This Note About This Developer NoteMac OS PowerPC G3 MicroprocessorSupplemental Reference Documents ATA DevicesUSB Devices Open FirmwareE F a C E Introduction Features Case and External Features Shows a front view of the computerFront view 2Side view showing I/O bay Compatibility Issues System SoftwareVideo RAM Expansion Modules Main RAM Expansion ModulesUSB Ports and Devices Page Architecture Architecture G3 Microprocessor Processor moduleBackside Cache Memory Controller and PCI Bridge Main Logic BoardController IC Video Display Subsystem USB ControllerBuilt-in Modem Infrared Link Module Devices and Ports USB Connectors USB PortsTransfer Types Supported GNDUSB Compatibility Issues ADB CompatibilityUSB Storage Devices Serial Port CompatibilityMacintosh-To-Macintosh Connections USB ControllerKeyboard Keyboard LayoutMouse Keyboard and USBHard Disk Drive Video DisplayInfrared Communication Link Sound SystemBuilt-in Microphone Sound InputsSound Outputs External Sound InputExternal Sound Output Sound SpecificationsHeadphone Jacks Total harmonic distortion Ethernet Port Internal ModemPage RAM Expansion Expansion Slots Removing the Logic Board AssemblyPlacing the Computer Face Down Removing the bottom cover Unfastening the CablesRAM Expansion 3Logic board assembly handle and retaining screws Removing the Retaining ScrewsRemoving the Logic Board Assembly Removing the EMI ShieldLocations of the Expansion Slots Main RAM Expansion 6Locations of the RAM expansion slotsMechanical Design of RAM SO-DIMMs Electrical Design of RAM SO-DIMMsSdram Devices Configuration of RAM SO-DIMMs RAM SO-DIMM Electrical Limits Address MultiplexingVideo RAM Expansion Page Software Why Make This Change? What Has Changed Features of the New Approach User Experience PerformanceRAM Footprint Data Structures and FilesBoot ROM Contents Mac OS ndrv Drivers RtasToolbox Image File Contents Trampoline Code NewWorld Boot ProcessToolBox ROM Image What Is Different Interrupt HandlingOutmoded Resources RAM FootprintNanoKernel Startup Disk Control PanelInterrupt Layout Open Firmware and the Device TreeMachine Identification Software Abbreviations Chrp NMI Page Index Nvram X, Y, Z Allen Watson