Hardware Troubleshooting Techniques

Working on Portable Systems

One of the biggest problems for portable computers is heat buildup inside the case. Because conventional power supplies (and their fans) are not included in portable units, separate fans must be designed in portables to carry the heat out of the unit. The closeness of the portable's components and the small amount of free air space inside their cases also adds to heat-related design problems.

The internal PC boards of the portable computer are designed to fit around the nuances of the portable case and its components, rather than to match a standard design with standard spacing and connections. Therefore, interchangeability of parts with other machines or makers goes by the wayside. The only source of most portable computer parts, with the exception of PC Cards and disk drive units, is the original manufacturer. Even the battery case might be proprietary. If the battery dies, you must hope that the original maker has a supply of that particular model.

Although adding RAM and options to desktop and tower units is a relatively easy and straightforward process, the same tasks in notebook computers can be difficult. In some notebooks, you must disassemble the two halves of the case and remove the keyboard to add RAM modules to the system. In other portables, the hinged display unit must be removed to disassemble the unit. Inside the notebook, you might find several of the components are hidden behind other units. Figure 3.14 demonstrates a relatively simple disassembly process for a notebook unit.

Figure 3.14 Disassembling a notebook computer.

In this example, a panel in front of the keyboard can be removed to gain access to the notebook's internal user-serviceable components. Four screws along the front edge of the unit's lower body must be removed. Afterward, the LCD panel is opened and the front panel of the notebook's chassis is pulled up and away to expose a portion of the unit's interior.

Troubleshooting PCMCIA Problems

One of the mainstays of portable computer products is the credit card-like PCMCIA cards, also known as PC Cards. The process for troubleshooting PC Cards is nearly identical to troubleshooting other I/O adapter cards.

PCMCIA cards can be plugged into the system at any time and the system should recognize them. In most cases, Windows 9x, Windows Me, Windows 2000, and Windows XP have a copy of the necessary driver software for the PCMCIA adapter being installed and will install it automatically when it detects the adapter. Most Windows operating system versions display messages telling you that they are installing the drivers required. However, Windows 2000 and Windows XP just install the drivers without a notice.

In cases in which the operating system does not have the necessary driver software, it prompts you for a path to the location where the driver can be loaded, when it detects the adapter. PCMCIA manufacturers typically supply drivers for various operating systems on a floppy disk or a CD that comes with the adapter.

To verify that the PC Card device is working, access Device Manager. If there is a problem with the PC Card device, it appears in Device Manager. If the PCMCIA adapter's icon shows an exclamation mark on a yellow background, the card is not functioning properly. Turn the system off and reinsert the device in a different PCMCIA slot. If the same problem appears, three possible sources of problems exist—the card might be faulty, the PC Card controller in the PC might be faulty, or the operating system might not support the device in question.

If the Windows Device Manager displays the PCMCIA socket but no name for the card, the card insertion has been recognized but the socket could not read the device's configuration information from the card. This indicates a problem with the PCMCIA socket installation. To correct this problem, remove the PCMCIA socket listing from Device Manager, reboot the computer, and allow the Windows PnP process to detect the socket and install the appropriate driver for it. If the names of the PCMCIA cards do not appear after the restart, the reinstallation process was not successful. Therefore, the PCMCIA socket you are using is not supported by the operating system version.

If the names of other PCMCIA cards do appear in the Device Manager, but the card in question does not, it is likely that the card has been damaged. To test the PC Card device, insert a different PC Card device of any type in the slot. If the other card works, it is very likely that the card in question has been damaged.

Troubleshooting Portable Unique Storage

As with other PCMCIA devices, PC Card hard drives are self-contained. Plug them into the PCMCIA slot and the system should detect them (they are hot-swappable). If the system does not detect the card/hard drive, use the troubleshooting steps described for other PCMCIA devices.

Troubleshooting Batteries

If you turn your portable computer on and nothing happens, the first things to check out include the power supply and the battery. If the power supply is plugged in, the computer should start up when the On/Off switch is engaged. However, if the computer is running on battery power and the system does not start up, the battery could be bad or need to be charged.

Verify that the battery doesn't need a recharge by trying to start the system with the AC power adapter plugged in. Check the power indicator in the system display panel. If it is on, power is being supplied to the portable. If the indicator is not on, verify that the power cord is securely connected to a live power source. Check all the power connections to ensure that the AC adapter jack is securely connected to the AC adapter port.

If the portable still doesn't start up, you must troubleshoot the system board. If the system runs from the AC adapter, the battery needs to be recharged or replaced.

Although a dead system is a classic battery/power-supply problem, you might encounter several other battery-related problems with portable computers. These include problems that present the following types of symptoms:

• You receive warning messages about the battery not charging.

• The computer experiences intermittent system shut downs when operating with only the battery.

• The computer does not recognize its network connection when operating with only the battery.

• The computer and input devices are slow when operating with only the battery.

• The computer loses the time and date information when operating on battery power.

A loose or improperly installed battery can cause these problems. They can also appear when the battery is toward the end of its charge/recharge cycle. Check the installation and attempt to recharge the battery using the portable computer's AC adapter.

The actual life of a laptop computer battery varies from just under one hour to over two hours in each sitting. If you are experiencing battery life cycles that are significantly shorter than this (for example, 10 to 15 minutes), you might have a problem referred to as battery memory.

Battery memory is a condition that occurs with some types of batteries in which the battery becomes internally conditioned to run for less time than its designed capacity (for example, if you routinely operate the computer using the battery for an hour and then plug it back in to an AC source, the battery can become conditioned to only run for that amount of time).

To correct battery memory problems, you must fully discharge the battery and then recharge it. To accomplish this, complete the following steps:

1. Turn the portable's Power Management feature off by accessing the Power Management icon in the Windows Control Panel.

2. Restart the computer and access the CMOS setup utility during bootup.

3. Disable the power management functions in the CMOS settings.

4. Start the portable computer using only the battery and allow it to run until it completely discharges the battery and quits.

5. Recharge the battery for at least 12 hours.

6. Repeat this process several times watching for consistently increasing operating times.

Troubleshooting Docking Stations/Port Replicators

Most docking stations offer an internal power supply that can operate the portable and its peripheral attachments: an external parallel port for printers, a serial port for serial devices (mice and modems), USB ports, external VGA/DVI video and full size keyboard connections, and audio connections for external speakers.

In addition, the docking station can host several types of external storage devices, including full-sized FDD/HDD/CD-ROM/DVD drives. Docking stations might also include one or two PCI slots that allow full-sized desktop adapter cards (SCSI or specialized video or LAN card) to be added to the system when it is docked. They might also provide multiple PCMCIA slots that add to the existing PC Card capabilities of the portable it is supporting.

For the most part, these connections are simply physical extensions of the ports provided by the portable. Therefore, if the port works on the portable and doesn't work when connection is made through the docking station, generally something is wrong with the docking station/port replicator. However, many portable computers employ special keystroke combinations (Fn + some other key) to activate external devices, such as a video display monitors or full-size keyboards.

For example, some portables detect that the external video display has been attached. Others use an Fn key combination to switch the display to the external monitor only, and then use another Fn key combination to send the display to both the LCD panel and the external display (that is, internal, external, or both).

If a peripheral device is not working, one of the first steps to take is to refer to the portable's documentation to ensure that the external device has been activated.

For audio problems, verify that the speakers are connected to the correct RCA mini jacks (not the Line IN or Microphone jacks). Check the documentation to ensure the sound output has not been muted using an Fn key combination.

On Windows operating systems, the hardware profile information for the portable computer can be configured differently for docked and undocked situations. When the computer is docked and turned on, its configuration is reset and the Eject PC option appears on the Start menu. However, when the computer is not docked, the Eject PC option is automatically removed from the Start menu.

The Windows 2000 and Windows XP Professional operating systems use hardware profiles to determine which drivers to load when the system hardware changes (docked or undocked). It uses the Docked Profile to load drivers when the portable computer is docked and the Undocked Profile when the computer starts up without the docking station. These hardware profiles are created by the Windows XP operating system when the computer is docked and undocked if the system is PnP compliant.

If a portable is not PnP compliant, you must manually configure the profile by enabling and disabling various devices present when docked and undocked.

The first check is to verify the power cord connection and docking power supply. Next verify that the portable has been properly inserted in the docking station or port replicator.

If a single docking station connection does not work, bypass the docking station/replicator and try to operate the peripheral directly with the portable unit. Check the power supply for both the docking station and the peripheral device and verify that both are turned on. Reboot the portable while it is attached to the docking station. Then check any signal cables between the docking station and the peripheral.

If the PS/2 mouse connection does not work, verify that it has not been installed in the PS/2 keyboard connector by mistake. Verify that the mouse port is enabled in the CMOS setup utility. Likewise, if you are using a USB or serial mouse, verify that the port is enabled in CMOS and that it is connected to the correct port.

Check the serial port's configuration settings to verify that a proper device driver has been installed for the mouse.

If the portable's touch pad works but the external mouse does not, check the computer's documentation for an Fn key combination requirement for the mouse.