Bài giảng Computer - Chapter 20

Chapter Overview Computer Disassembly and ReassemblyUpgrading a Computer 1Preparing to Work on a Computer Documentation is key to preparation.Collect the following before starting a job: Computer configuration sheetComputer and motherboard documentationList of all installed expansion cards Operating system (OS) documentationA plan of action that includes a checklist of tasks, tools, and parts 2Questions to Ask Before Starting a Job Is this the right computer?Why am I taking it apart?Do I have everything necessary to do the job?Do I need more information before starting the job?Are there any proprietary hardware components in this machine?Do any of these tasks require the assistance of a third-party technician? 3Tools and Components Assemble a toolkit that contains standard tools and a DOS boot floppy disk.During planning, ensure that you have all items required. Have on hand: The original OS disksA rescue disk for the version of Microsoft Windows you are working withThe correct utilities for the OS version Virus-checking utilities, with up-to-date signature files 4Disassembling a Computer Removing the computer case gives you access to memory, expansion slots and cards, and the CPU.Each computer brand has some custom components or layout.Use the manual and other documentation that came with the computer.The extent to which you have to disassemble a computer depends on the specific problem or repair. 5Procedure for Disassembling a Computer Make a complete backup of necessary OS and working files. Document the system (hardware and software). Create a clean work area with plenty of room and light. Gather all the necessary tools for the job. Implement all proper safety procedures. Turn off the computer. 6Procedure for Disassembling a Computer (Cont.) Disconnect the power cables. Wear an antistatic wrist-grounding strap. Locate the screws for the cover. Remove the screws. Remove the cover from the computer. Document the location of expansion cards and drives. 7Procedure for Disassembling a Computer (Cont.) Remove all the cards and place them in antistatic bags. Document the location and connections for each drive. Remove the interface and power connection cables. Remove the drives from their bays.Remove the motherboard. 8Reassembling a Computer Follow the disassembly procedure in reverse order.Do not force connectors into place. Do not force expansion cards into the slots. When removing cables, remember the pin 1 locations.Connect the cables to the drives before installing the drives in the bays.Test the system before replacing the cover. 9Preparing to Upgrade: the Configuration Sheet 10Memory As programs and hardware get faster, memory is more important.Memory upgrades are simple to perform.Purchasing the right type of memory is critical.Consider memory chip format, speed, extended data out random access memory (EDO RAM), parity, and cache memory.Check the motherboard documentation to determine the memory type, population scheme, and location of memory slots.Two basic formats for memory are single inline memory modules (SIMMs) and dual inline memory modules (DIMMs). 11SIMM FormatsContains memory in 8-bit chunksA 32-bit processor requires four SIMMsContains memory in 32-bit chunksA 32-bit processor requires one SIMM30-Pin SIMM72-Pin SIMM12DIMM Formats DIMMs are easier to install than SIMMs. A “key” or notch cut into one edge prevents incorrect installation.When you buy a DIMM, you must know the exact memory type. DIMMs are found in larger memory sizes than SIMMs. 13Memory Considerations Memory speed is measured in nanoseconds (one-billionth of a second). The lower the number, the faster the chip speed.All chips in the same computer should run at the same speed.Typical speeds are 50, 60, 70, and 80 nanoseconds.The motherboard documentation should list the appropriate speed. 14EDO RAM EDO RAM can improve read times and overall performance by up to 30 percent. The chip outputs data from one address while setting up a new address. 15Parity Parity is used to check the reliability of data. Parity requires an additional bit.Memory can be purchased with or without parity; the cost is higher with parity.System specifications indicate if parity is required.Parity and nonparity chips cannot be mixed.Some systems allow parity to be turned on or off in the basic input/output system (BIOS). 16Cache Memory L1 cache is built into the processor and cannot be changed.L2 cache can be built into the processor or on the motherboard.Check the motherboard documentation to determine if you can upgrade the L2 cache. 17Installing a SIMM18CPU Upgrades CPU upgrades are becoming less common.The first task is to determine if the CPU can be upgraded and which CPU upgrade will work.The motherboard documentation specifies compatible CPUs.Check on required BIOS upgrades or jumper settings.A new motherboard is required for upgrading a 386 to a Pentium or a Pentium to a Pentium III, or for CPUs from different manufacturers. 19General Procedure for Installing a CPU Turn off the computer and unplug the power cord.Disconnect external devices (AC power and monitor power).Follow the appropriate electrostatic discharge (ESD) safety precautions.Remove the cover of the computer.Locate the socket for the CPU on the motherboard. Remove the old processor. 20General Procedure for Installing a CPU (Cont.) Install the new processor by aligning the chip properly. Set any jumpers or switches on the motherboard. Reconnect any peripherals (keyboard, mouse, monitor).Replace the cover and power up the computer.Make changes to the BIOS, if required, using the complementary metal-oxide semiconductor (CMOS) setup program. 21Additional Considerations for Installing a New CPU Some CPU upgrades require installing a new voltage regulator and cooling fan.In motherboards that support more than one CPU, all CPUs must be of the same type and from the same manufacturer.Some Pentium II and later motherboards have a special card that is inserted in any empty CPU slot. 22Expansion Cards Install an expansion card to add faster video, add more ports, or improve sound quality.Ensure that the expansion card will work in the system to be upgraded.Ensure that the appropriate drivers are available for the OS. 23Considerations for Installing an Expansion Card Ensure that adding a new card is the most cost-effective way to upgrade. If no expansion slots are available, free up space by Replacing single-port cards with one multifunction cardUsing a Small Computer System Interface (SCSI) card and a chain of SCSI devicesUsing a universal serial bus (USB) if available 24Considerations for Installing an Expansion Card (Cont.) Ensure that the card fits in the slot and matches the bus type of the motherboard.Document available I/O ports and interrupt requests (IRQs) on the system.Ensure that enough RAM is available to support the device and driver.Ensure that a direct memory access (DMA) channel is available if required.Identify potential conflicts with other cards and devices.Obtain the appropriate driver for the OS. 25Installing a Non–Plug and Play Expansion Card Read the expansion card documentation and note special requirements.Check the computer configuration to determine available I/O addresses and IRQs.Configure jumpers or switches on the card if required.Turn off the computer and unplug the power cord. 26Installing a Non–Plug and Play Expansion Card (Cont.) Follow the appropriate ESD safety precautions.Remove the cover from the computer.Install the card in a free slot and power up the computer.Replace the cover.Power up the computer.Install any software drivers or applications. 27Installing a Plug and Play Expansion Card Plug and Play allows for changes to computer configuration with minimal intervention.Plug and Play devices allow the system to configure the card.To allow Plug and Play devices to work immediately, the computer hardware, OS, and card must all be Plug and Play compliant.Some systems require enabling Plug and Play in the system BIOS. 28Considerations for Installing Hard Disk Drives Ensure that the drive fits. If not, use a SCSI, USB, or parallel port interface drive.Ensure that the system BIOS supports the size of the new drive.Ensure that the drive controller supports the new drive.Ensure that you have enough cables to install the drive. 29Preparing to Install an Integrated Device Electronics (IDE) Drive Hardware preparation consists of ensuring that You have the correct driveThe drive fits into the computerYou have the proper cables to connect the drive Software preparation consists of having a floppy boot disk with the format and fdisk utilities. 30Installing an IDE Drive Collect all necessary documentation for the drive and computer.Back up any data you want to keep.Turn off the computer and unplug the power cord.Follow the appropriate ESD precautions.Open the computer case. 31Installing an IDE Drive (Cont.)Check the documentation and set the jumpers for the drive, if required.Connect the cable to the drives.32Installing an IDE Drive (Cont.) Connect the power connection cable.Install the drive in its bay.Reconnect the computer power and boot up the system. Run the CMOS setup program if necessary. 33Additional IDE Drive Installation Considerations Set up and test a drive before final installation in the bay. Avoid ESD and protect the drive from overheating.Use disk management software in older systems that require it. 34Additional Steps After the Physical Installation Boot the computer from the bootable floppy disk, and run fdisk to create and set the partitions.Format the drive. If it is the only drive, format it with system files.Replace the cover on the computer. 35Operating System Driver Installation Device driver setup is no longer a complex task.Microsoft Windows 98, Microsoft Windows Me, and Microsoft Windows 2000 have reduced the need for manual intervention.Windows recognizes and configures Plug and Play devices automatically.A wizard installs the appropriate drivers and resolves any device issues. 36Using the Add/Remove Hardware Wizard37Motherboard Installation Considerations Replacing the motherboard may be the most inexpensive way to completely overhaul a computer.Some motherboards are proprietary and can be replaced only with one made by the same manufacturer.The motherboard must fit into the existing case. The motherboard must have the same built-in COM and LPT ports as the old one.You should determine if the new motherboard has a built-in video card. 38Motherboard Installation Considerations (Cont.) The new motherboard must accommodate the existing expansion cards.The power supply connector should be as close to the power supply as possible. The existing drives must work with controllers on the new motherboard.The memory on the old motherboard must work with the new one.The upgrade should meet your current and future requirements. 39Replacing a Motherboard Replacing a motherboard is similar to building a computer.The procedure is as follows: Complete an installation checklist.Follow the steps for disassembling a computer.Check the settings on the new motherboard. 40Replacing a Motherboard (Cont.) Install the new motherboard. Reconnect the case switches. Follow the steps for computer reassembly (outlined in Slide 9). Test the computer to ensure that it boots.Complete the final testing and close the case. 41Chapter Summary Preparation is key to a successful upgrade or repair. Document everything. Have a complete toolkit and take safety and ESD precautions.Memory is probably the simplest upgrade performed by a technician.Installing a new CPU and installing an expansion card are common ways to upgrade older computers.Installing a new drive is not difficult when you follow the procedure carefully.Installing a new motherboard completely overhauls the computer. 42