May 24, 2011, 8:06 a.m.
posted by shadow
The two main disadvantages of notebook PCs are that they are difficult to work on and upgrades are expensive. Upgrade parts are expensive because they are usually proprietary and not generally interchangeable between manufacturers — or even between models from the same manufacturer, in many cases.
Time Shaver You can assume the following three guidelines about questions regarding repairs on a portable PC:
The type of portable PC in question is a notebook computer, unless otherwise stated.
The notebook computer has a Pentium or higher CPU.
The only upgrades that are performed internally are to the RAM and hard drive.
RAM upgrades (at least on most high-end and name brand portable PCs) are accomplished through a porthole or trap door on either the bottom or the side of the portable PC. Many different memory technologies can be inserted into a portable PC, but the first rule is not to mix memory types. The module sizes are now large enough that memory types shouldn’t need to be mixed. See Chapter 7 for more general information on memory types.
Instant Answer After installing new RAM in a notebook PC, if the RAM doesn’t appear in the BIOS POST display, the RAM probably isn’t properly seated. Shut down the notebook and reseat the RAM.
Notebook PCs and many other portable computers use Small Outline Dual In-line Memory Modules (SODIMMs). A SODIMM is a smaller, narrower, and taller version of the DIMM that is used in desktop PCs. On most newer notebook designs, memory is added through the bottom of the PC’s case, as shown in Figure. The SODIMM is mounted flush to the main board and lies flat to save space.
Figure: Some newer portable PCs have openings on the case into which a memory module (a DDR SODIMM is shown) is installed.
For information on how a SODIMM module is installed, see the section “Getting Ready for Work,” later in the chapter.
Working with smaller portable devices
Palmtop computers and other handheld computing devices don’t have the overall physical size or internal case space to accommodate full-sized memory modules. For these systems, smaller memory modules have been developed, such as the microDIMM. Such a module is shown in Figure.
Installing memory in older portables
Older notebook PCs may use Single In-Line Memory Modules (SIMMs), which are installed in much the same manner as the SODIMM. However, a portable system often prescribes both the total memory that it can support and the increments that you can use to add it. Consult the owner’s manual to determine the right choices.
Another way to add memory to a PC is to insert a PC card, also known as a Personal Computer Memory Card International Association (PCMCIA) card. (See the section “Focusing on PC cards,” later in this chapter, for more information on PC cards.)
The secondary storage units of some notebook models are under the keyboard for easy interchange or replacement. In these models, replacing the hard drive is a snap: Snap out the old and snap in the new. On other models, however, the hard drive is internally blended into the notebook’s system. If you really want to increase the hard drive space, you may want to use a less arduous way of increasing the PC’s storage capacity.
The following is a list of options that you should try before attempting to replace an internal hard drive on a notebook PC:
You can easily add removable storage through an existing port. For example, you can add a Zip, Jaz, or tape drive via a serial, parallel, or USB port.
You can add a hard drive card in a PC card slot or add a USB-port drive or compact flash (CF) card.
If a portable PC supports it, you can interchange the floppy disk or CD-ROM drive with a second removable hard drive.
You can use disk space compression utilities to increase the effective space of the hard drive.
Notebooks and other portable computers don’t have standard internal layouts and designs like those provided by the form factors of desktop and tower PCs. Because of this, you need an upgrade kit to change the hard drive in a notebook PC. The upgrade kit usually includes the new hard drive, a PC card, and data transfer cables. The PC card and cables are used with data transfer software that is also included in the kit to temporarily hold and transfer the data from the old hard drive to the new one.
PCMCIA offers a standard for adding more memory and peripherals to portable computers using credit card–like cards — also called PC cards. All PC cards are 85.6 mm long and 54 mm wide, or approximately 3.4 inches by 2.1 inches, and use a 68-pin connector. PC cards are matched to designated slots on the portable PC, and each is defined to one of the three types and sizes of cards.
Remember The three types of PC card slots are as follows:
Type I: At 3.5 mm thick, these slots have one row of sockets and are used primarily to add flash memory, or SRAM (static RAM). This type of memory is common on PCMCIA cards because it requires less power. You can read more about flash memory in Chapter 4.
Type II: At 5.5 mm thick, these slots have two rows of sockets and are used to add modems and NICs to a notebook computer. These cards usually have a pop-out connector for an RJ-11 or RJ-45 connector.
Type III: At up to 10.5 mm thick, these slots have three rows of sockets and are used to install hard drives or support adapters for external CD-ROM, DVD, and tape drives.
More information is available on PC card standards from PCMCIA’s Web site (www.pc-card.com).
The magic of the PC card
Adding a function through the PC card slots of the notebook PC is as easy as pressing the card (firmly) into its slot. You can even do this while the notebook is running. The card’s function is instantly recognized by the PC — provided that the card services and sockets are running.
Remember Portable PCs contain the following layers of software to detect and support a PC card when you insert it into the computer:
Socket services: A layer of BIOS-level software that detects when a card is inserted or removed
Card services: Software that manages the assignment and allocation of system resources to the PC card, such as IRQ and I/O addresses, after the socket services software has detected the card
Instant Answer Expect at least one of the following questions about PC card types:
The higher the type number, the thicker the card. Hard drives (Type III) are thicker than modems (Type II), which are thicker than memory (Type I).
Remember which card type supports which device type. Type I cards are typically memory cards; Type II cards are commonly communications-oriented, such as a modem or a NIC; and Type III cards are secondary storage, such as a hard disk drive, or an adapter interface for an external peripheral device.
Hot-swapping lets you change PC cards without shutting down the system. You can remove an existing card from its slot and install a new card while the PC is on and the operating system is running.
Instant Answer Expect a question on hot-swapping, such as, “What is changing a PC card without powering off the system called?”
PC cards use the 32-bit CardBus standard, which is essentially identical to the PCI bus architecture with some minor electrical differences. CardBus supports bus mastering, accommodates cards at different voltages, and includes advanced power-management features that can idle or turn off PC cards to increase battery life.
The PCI bus, the major crosstown bus of the desktop PC, has been adapted to the smaller footprint of the portable system. The following two primary PCI adaptations are used on systems with smaller physical sizes:
Compact PCI (CPCI): This PCI adaptation is used primarily for industrial computer applications that need a smaller and more robust form factor than is used with desktop PCs. CPCI, an open standard developed and supported by the PCI Industrial Computer Manufacturer’s Group (PICMG), is well suited to small, high-speed industrial applications with several high-speed card interfaces.
Mini-PCI: This is a smaller version of the standard desktop PC PCI form. The mini-PCI has all the same features and functions of a standard PCI card while being only about one-fourth the size of the larger standard card. Adapters are available that allow full-sized cards to fit into the mini-PCI slot and vice versa. The mini-PCI is commonly used for internal wireless network adapters on portable PCs and hand-held devices.
Liquid crystal displays (LCDs) are used on notebook computers because LCDs have lower power requirements than the CRT-style monitor and can be configured into a flat panel.
Active matrix: If you have an LCD on your watch, you have an active matrix display. This type of LCD has a transistor for each pixel and creates a crisp image that is easy to read from an angle and has sharp resolution. The downside is that all those transistors take a lot of power. An active matrix display can run down a battery in less than 2 hours. Active matrix displays are TFT (Thin-Film Transistor).
Passive matrix: This type of LCD has two groups of transistors: one along the top edge of the display, containing one transistor for each vertical column of pixels, and the other along the left side of the display, containing one transistor for each horizontal row of pixels. Wires form a matrix that interconnects the transistor rows and columns. To darken a particular pixel, power is sent to the transistors on the same row and column as the pixel and down the wires to the intersection point where the pixel sits. This method uses much less power, but it is much slower and produces a lower-quality image. Passive matrix displays are usually either the older Double-Layer Supertwist Nematic (DSTN) or the newer High-Performance Addressing (HPA). HPA improves the response of the display over DSTN, but both produce an inferior image compared to active matrix (TFT) screens.
Both types of LCDs are flat and about 1⁄2-inch thick. TFT displays produce the best image and cost the most. HPA and DSTN screens are hard to see except by looking straight at the display. An HPA screen has one advantage: Only the operator has a clear view of the screen. People trying to see the screen from the side are out of luck, which may be desirable when working with secure data.
Tip Because LCDs are covered with a thin sheet of plastic, avoid any abrasive cleaners and cloths. Use a mild detergent or a low-sudsing, general-purpose cleaner and a lint-free soft cloth.
The graphics display resolution standards supported on portable PCs are the same as those available on desktop monitors and PCs. For the most part, four standards are the primary standards supported on active displays. The four standards supported on portable PCs are:
Super video graphics array (SVGA): This is an extension of the video graphics array (VGA) standard, that supports 1024 x 768 and higher resolutions.
Extended graphics array (XGA): The standard in use today is actually XGA-2, based on the original IBM XGA standard introduced in 1990. This standard supports non-interlaced resolution of 1024 x 768 and higher.
Super extended graphics array (SXGA): An extension of the XGA standard that can support 1280 x 1024 with 1.3 million pixels in the display.
Ultra extended graphics array (UXGA): A further extension of XGA that supports 1600 x 1200 resolution.