Troubleshooting PC Storage Devices

This chapter is from the book

PC Help Desk in a Book: The Do-it-Yourself Guide to PC Troubleshooting and Repair

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This chapter is from the book

This chapter is from the book 

PC Help Desk in a Book: The Do-it-Yourself Guide to PC Troubleshooting and Repair

Learn More Buy

Troubleshooting Drive Detection Problems

Your computer can't prepare a new hard disk or use removable-media or optical disks until it recognizes the drive. Symptoms of a drive not being recognized can vary with the type of drive interface (ATA/IDE, USB, IEEE-1394, SCSI, parallel port).

The following are some typical symptoms:

• Internal drives aren't displayed at startup on systems that display configuration information

• SCSI BIOS on SCSI host adapter cards used with hard disks can't locate drive

• ATA/IDE BIOS on ATA/IDE host adapter cards used with fast, large hard disks can't locate drive

• Hard disk isn't displayed in drive preparation utilities like Computer Management (Windows XP/2000) or FDISK (Windows 9x/Me)

• Proprietary disk-preparation or disk setup programs supplied with IEEE-1394, parallel port or USB drives can't locate drive

Table 3.1 provides a quick-reference to the most common reasons drives aren't recognized by the system. See detailed solutions in the sections following the table.

Table 3.1 Quick-Reference to Drive Detection Problems

*Count the number of ridges in a drive cable to determine the number of wires (if necessary).

Troubleshooting an ATA/IDE Drive

An IDE/ATA drive cannot be detected by the system if any of the following are true:

• The drive is not connected to power or the power cable is loose—During installation of the drive, be sure to firmly connect the drive to a power cable coming from the power supply. If you use a Y-splitter or power cable extender, be sure the splitter or extender is in good condition and is firmly connected to the power cable and to the drive.

• The drive is not properly connected to the ATA/IDE interface on the motherboard or add-on card—Some low-cost cables are not keyed, making it possible for the cable to be installed upside down at either the host adapter or drive end.

• The drive is configured as "Not present" or "none" in the system BIOS—The drive should be configured using the Auto setting to enable the drive to report its configuration to the system.

• The drive is not jumpered correctly—The older 40-wire cables require that one drive be jumpered as master and the other as slave; some brands of drives don't use jumpers if only one drive is on the cable. 80-wire cables use cable select jumpers for both drives, using the position of the drive on the cable to determine which drive is the primary (master) and which the secondary (slave) drive.

In the following sections, you will learn how to check an existing drive installation for problems; if you are installing a brand-new ATA/IDE drive, you can follow the same steps to make sure you are performing the installation correctly.

Checking the Drive Connection to the Power Supply

Most ATA/IDE drives use a four-pin Molex power connector, while a few removable-media drives use a small four-pin power connector instead. In either situation, the drive must be connected to a matching lead from the power supply.

If the power supply doesn't have a free connector available, you can disconnect a power cable from another device and attach a Y-splitter to the end of the cable to enable two devices to be powered from a single cable (see Figure 3.1).

It takes a bit of force to make a solid connection with the Molex connectors seen in Figure 3.1; make sure the drive is attached solidly to the power cable.

Checking the Drive and Host Adapter Connection to the Data Cable

The connection between the ATA/IDE host adapter and the drive is made with a 40-pin cable. If the cable is not connected correctly to either the host adapter or the drive, the drive will not be detected and cannot be used.

The contrasting-colored markings on the cable indicate pin 1; line up this side of the cable with pin 1 on the drive and the host adapter. In almost all cases, the location of pin 1 is next to the power connector (see Figure 3.2). Most drives also indicate the location of pin 1 on the bottom or rear of the drive.

Figure 3.1 A typical ATA/IDE hard drive attached to a Y-splitter power cable before installation into a system.

Figure 3.2 Data cable connections to a typical ATA/IDE drive. Pin 1 should be next to the power connector.

Note that some cables don't have a plugged hole or a raised protrusion to prevent the cable from being inserted incorrectly (see Figure 3.3).

On some systems, if the ATA/IDE cable is connected in reverse, the computer will not display anything on the screen after you turn on the system. This is because some computers can't continue the power-on self test (POST) until a connected ATA/IDE hard drive responds to a spin up command. Because the drive can't receive the command from a reversed cable, the computer can't proceed in the POST process and can't display any messages.

Figure 3.4 shows how an ATA/IDE cable should be attached to the host adapter. Note the markings for pin 1 on the motherboard and how the keyed cable prevents incorrect installation.

Figure 3.3 Keyed (top) and unkeyed (bottom) ATA/IDE data cables.

Figure 3.4 An 80-wire ATA/IDE cable properly attached to the host adapter on the motherboard.

Configuring the Drive Jumpers

Depending on the type of ATA/IDE cable used to connect drives to the host adapter, the jumpers or the position of the drives on the data cable are used to determine which drive is primary and which is secondary.

Jumpers are pins on the rear (or, occasionally the underside) of a drive that are closed with jumper blocks to set the drive's configuration. ATA/IDE drives have three basic configurations, which can be selected with jumper blocks (see Figure 3.5):

• Master—A drive jumpered as master becomes the primary drive on the cable; if you have your hard disk and optical drive on the same cable, the hard drive should be jumpered as master, and the cable should be plugged into IDE connector number 1 on the motherboard.

• Slave—A drive jumpered as slave becomes the secondary drive on the cable.

• Cable select—The position of the drive on the cable determines which drive is master and which is slave; requires an 80-wire Ultra ATA cable.

Figure 3.5 shows the most common jumper location and the various jumpering options supported on a typical hard disk.

Some drives have additional configuration options that are designed to handle BIOS limitations on some systems. For example, Western Digital hard drives that are not recognized at full capacity on systems with older BIOS chips can be configured with two jumper blocks; installing the second jumper block reduces the drive capacity that's reported to the system BIOS, enabling the drive to be handled by the system BIOS. But, to use the full capacity of the drive, the user must install the drive with Western Digital's EZ-Install or Data Lifeguard Tools, which load a special driver to override the BIOS's disk capacity limitations.

Figure 3.5 The jumper pins and jumpering options available for Western Digital hard disks.

Table 3.2 lists the jumper options for both 40-wire and 80-wire cables. I recommend using an 80-wire cable, even if you don't use drives that are designed for the faster speeds it accommodates, because the additional wires provide cleaner, better signaling to all types of ATA/IDE drives.

Table 3.2 Correct Jumpering for a New ATA Drive Installation

If you install two different brands of drives on the same ATA/IDE cable, in some cases, one or both drives might not be recognized, even if you jumper and connect them correctly to the data cable. This is because of manufacturer-specific differences in their implementation of the ATA/IDE standards.

To avoid this type of problem, I recommend you install the same brand of drive originally used in your system. To see the brand and model of the current drive in your system, open the Device Manager in Windows and open the disk drives category.

However, if you've already purchased a hard drive that won't coexist on the same cable with your current drive, here are some solutions you can try:

• Swap the drive positions on the cable—Use master and slave jumper positions rather than the default cable select jumper positions for an 80-wire cable to preserve the current drive letter sequence.

• Move the new drive to the secondary IDE cable—If you already have an optical or removable-media drive connected to the cable, it's acceptable to install the new drive as a slave. This eliminates any possibility of drive conflicts, since each hard drive is on a separate cable.

• Install an ATA host adapter into an empty PCI expansion slot on your computer and connect your new drive to it—Using the ATA-100 or ATA-133 host adapters packaged with some drives and available separately from various sources will also enable you to bypass BIOS limitations you might have with an older system, and could help your system run faster.

Determining When Your ATA/IDE Drive Has Failed

Although today's ATA/IDE hard drives are extremely reliable, it's still possible the drive itself has failed. Look for these indications of drive failure:

• Drive will not power up—To check this, shut down the computer, place your hand on the top of the drive case and turn on the computer. If you can't feel any vibration through the case (or you can't hear the drive turning) and the drive is connected to a working power supply, it's probably dead.

• Drive makes excessive noise when the system is turned on—If the drive sounds like it has a marble loose inside, makes scraping or coffee-grinder noises as soon as you turn it on, it's sustained physical damage and is probably dead.

• Computer won't turn on when the drive is attached to the power supply—If your computer appears to be dead when you start it with the drive attached, but powers up normally when you disconnect the power supply from the drive, the drive has a short-circuit and is probably dead.

If ATA/IDE optical and removable-media drives don't display any power lights at any time and won't spin up when you insert media, check their power, data cable, and jumper configuration as described previously.

If the drive's configuration checks out okay, and another drive works when connected to the same cable, the original drive is certainly damaged or dead and should be replaced.

Troubleshooting an IEEE-1394 Drive

IEEE-1394 drives are the newest way to add a high-performance hard drive to your system. They offer Plug-and-Play installation, hot-swap capabilities, and capacities rivaling desktop drives. However, if any of the following are true, your drive won't be detected by your system and can't be used:

• Disabled IEEE-1394 port on your computer

• Resource conflict between IEEE-1394 port and another device

• Drive is not powered on

• Your computer uses a version of Windows that doesn't support IEEE-1394 devices

• You haven't installed the correct drivers for your version of Windows and your drive

Before you connect an IEEE-1394 drive to your system, make sure the port is enabled and supported by your version of Windows. To do this, open the Device Manager and verify that the port is listed and that it is not reporting any problems.

To check your version of Windows for IEEE-1394 compatibility, see "Windows Limitations," Chapter 1. Also, make sure you have drivers for your drive and version of Windows. You might need to download drivers for your version of Windows from the manufacturer, particularly if you use Windows XP.

For details, see "Using the Device Manager," p. 480 for details.

Troubleshooting Problems with Your IEEE-1394 Port

If the IEEE-1394 port is not displayed in Device Manager then you must enable the port.

If the port is built in to your system, restart the computer, access the BIOS setup program, and enable the port (see Figure 3.6). Save changes and exit the system.

Figure 3.6 Enabling the IEEE-1394 port with the computer's BIOS setup program.

If the port is on an add-on card, use the Add Hardware wizard to detect the port and install drivers.

If the port is present but reports problems then you must correct these problems before you can expect the port or your drive to function normally. Some of the problems you might encounter could include

• Incorrect driver loaded for the port's chipset

• Hardware resource conflict with another port

• Corrupt driver loaded

• Device is disabled

For more details about using the system BIOS setup program, see "BIOS Setup," p. 104.

For more details about using the Add Hardware wizard, see "Add Hardware," p. 469.

These problems can be detected and resolved with the Windows Device Manager (see Figure 3.7).

Figure 3.7 A disabled IEEE-1394 port as displayed by the Windows XP Device Manager.

For details, see "Using Device Manager," p. 480.

Troubleshooting Other Problems with an IEEE-1394 Drive

If the port is working but the drive is not detected when you attach it to the system

• If the drive's instructions require you to install driver or configuration software before you attach the drive, disconnect the drive from the system, install the software, and reconnect the drive.

• Unplug the device cable from the IEEE-1394 port on the computer and reattach it.

• Make sure the drive is connected to AC power (if it isn't powered by the port) and turned on.

• If the IEEE-1394 ports on the computer are connected to the motherboard by a header cable (see Figure 3.8), make sure the cable is properly and securely attached to the motherboard.

Figure 3.8 Two typical locations for built-in IEEE-1394 and USB ports on the rear of a computer.

• Make sure that the IEEE-1394 cable is attached securely to the drive.

• If, after you've reconnected the power and IEEE-1394 cables, Windows does not automatically detect the device, run the Add Hardware wizard. Open the Control Panel through the Start menu, click Add Hardware (called Add New Hardware on some Windows versions), and follow the prompts to detect and install your new drive.

• Replace the IEEE-1394 cable if the drive still can't be detected, and retry.

Determining Your IEEE-1394 Drive Has Failed

If you've checked your software and hardware configuration as described above but your drive still won't function, it might be damaged or dead. This is particularly likely if the drive won't spin up or makes a lot of noise while running. However, if you have other IEEE-1394 devices connected to your computer and none of them are working, the host adapter is probably defective; contact the vendor for help.

Troubleshooting a USB Drive

The USB interface is a flexible interface used for many devices, including portable hard drives. USB hard drives offer Plug-and-Play installation, hot-swap capabilities, and capacities rivaling desktop drives. However, if any of the following are true, your system won't detect your drive:

• USB ports on your computer are disabled; a device connected to a disabled port cannot be detected until the port is enabled.

• The USB data cable is too long or is defective.

• A resource conflict exists between the USB port and another device.

• Drive is not powered on.

• Your computer uses a version of Windows that doesn't support USB devices.

• You haven't installed the correct drivers for your version of Windows and your drive.

• Your drive requires more power than the USB port can provide.

Troubleshooting USB Port Configuration

Before you connect a USB drive to your system, make sure the port is enabled and supported in your version of Windows. To do this, open the Device Manager and verify that the port is listed and that it is not reporting any problems. Also, make sure you have drivers for your drive and version of Windows. You might need to download drivers for your version of Windows from the manufacturer, particularly if you use Windows XP with the newer USB 2.0 ports and devices. Depending upon the drive, you might need to install its drivers first before you connect the drive to the system; check the drive's documentation to find out.

If the USB port is not displayed in Device Manager then you must enable it. If the USB port is built in to your system (as on most recent computers), restart the computer, access the BIOS setup program, and enable the port. Save changes and exit the system. If the port is on an add-on card, use the Add New Hardware wizard to detect the port and install drivers.

Troubleshooting Other Problems with USB Drives

If the USB port is working but the drive is not detected when you attach it to the system or doesn't work after being detected

• Unplug the cable from the USB port on the computer and reattach it; check the cable for damage.

• Make sure the drive is connected to AC power (if it isn't powered by the port) and turned on (if it has a power switch).

• Make sure that the power and USB cables are attached securely to the drive.

• Make sure the USB cable is attached securely to the computer.

• Unplug the drive from the USB port and reinstall the drive installation software provided by the vendor.

• If the drive is supposed to be detected by the system and prompt you for drivers, run the Add New Hardware wizard after connecting the drive to the system and powering it up if it isn't detected automatically.

See "Using Device Manager to Troubleshoot USB Devices," p. 338 for details.

To determine which version of Windows you use, see "Windows Limitations," p. 148.

For more details about using the system BIOS setup program to troubleshoot USB devices, see "Using the System BIOS to Solve Problems with USB Devices," p. 348.

For more details about using the Add Hardware wizard, see "Add Hardware," p. 469.

For details, see "Using Device Manager," p. 480.

• Open the properties sheet for the USB hub the drive is connected to and check the available power for that hub.

All recent versions of Windows (Windows 98, Me, 2000, XP) support USB 1.1 ports; USB 2.0 is supported in all of these Windows versions except for Windows 98 First Edition.

However, as with any device, you need to make sure you have drivers for your drive and version of Windows. You might need to download drivers for your version of Windows from the manufacturer, particularly if you use Windows XP.

If the USB port is not displayed in Device Manager then you must enable the port. If the port is built in to your system, restart the computer, access the BIOS setup program, and enable the port. Save changes and exit the system.

If the port is on an add-on card but the card wasn't detected when the computer was started, use the Add Hardware wizard to detect the port and install drivers.

If the port is present but reports problems, you must correct them before you can expect the port or your drive to function normally. Some of the problems you might encounter could include

• Incorrect driver loaded for the port's chipset

• Hardware resource conflict with another port

• Corrupt driver loaded

• Device is disabled

These problems can be detected and resolved with the Windows Device Manager.

If the USB port is working but the drive is not detected when you attach it to the system

• Unplug the device cable from the USB port on the computer and reattach it.

• Replace a damaged or suspect USB cable with a known-working cable of the same length (or shorter) and retry.

• Make sure the drive is connected to AC power (if it isn't powered by the port) and turned on.

• USB ports located on the rear of the computer are connected directly to the motherboard (refer to Figure 3.8), but USB ports on the front of the computer might be connected to the motherboard with a header cable. If the USB ports on the computer are connected to the motherboard by a header cable, make sure the cable is properly and securely attached to the motherboard.

• Make sure that the cable is attached securely to the drive.

• If, after you've reconnected the power and data cables, Windows does not automatically detect the device, reinstall the installation software provided with the drive or use the Add Hardware wizard (check the drive documentation for which installation process is recommended). To use Add Hardware, open the Control Panel through the Start menu, click Add Hardware (called Add New Hardware on some Windows versions) and follow the prompts to detect and install your new drive.

For more details about using the Add Hardware wizard, see "Add Hardware," p. 469.

• If the drive is connected to a bus-powered generic USB hub (such as those built into keyboards and monitors) and the drive itself is bus-powered, connect the drive directly to the USB root hubs (ports) on the front or rear of the system if possible; root hubs provide the USB maximum of 500mA per port. If this is not convenient, connect the drive to a self-powered USB hub (which also provide 500mA per port) and connect the hub to the computer. Bus-powered hubs provide no more than 100mA of power per port, while bus-powered removable-media drives could require almost 500mA of power to run (see Figure 3.9).

Determining the USB Drive Is Defective

If you've checked your software and hardware configuration as described above, but your drive still won't function, it may be damaged or dead. This is particularly likely if the drive won't spin up or makes a lot of noise while running, but other devices attached to the USB port are working correctly.

However, if no devices attached to the USB port are working, the motherboard or host adapter containing the USB port is probably defective; contact the vendor for help.

Figure 3.9 The USB Mass Storage Device (drive) isn't working because it draws more power than a bus-powered hub can provide.

Troubleshooting a SCSI Drive

Although SCSI drives were actually developed before ATA/IDE drives, they're not nearly as popular as other types of drives in desktop computers. However, SCSI drives and other types of devices are popular choices for high-performance video and graphics editing workstations and for servers. SCSI drives can't be recognized by the system if any of the following are true:

• Incorrect termination of the ends of a SCSI daisy-chain

• Duplicate device ID numbers in a daisy-chain

• Drive not powered on

• SCSI interface not enabled

• SCSI interface has resource conflicts with another device

• Incorrect cable used to connect the drive

Troubleshooting Termination and Device ID Settings

If you have added a drive to a system with other SCSI devices on-board, you might need to adjust termination settings for the existing and new drives/devices. The ends of any SCSI daisy-chain must be terminated to allow the host adapter to properly detect and control all devices. See Figure 3.10 for typical configurations. If you connect the new drive to the end of the daisy-chain, you need to disable termination on the device that was formerly at the end of the daisy-chain and enable termination on the new drive.

Figure 3.10 A properly configured SCSI device daisy-chain.

You also might have a duplicate device ID. Some SCSI host adapter vendors, such as Adaptec, offer a SCSI diagnostics program that can list the device IDs already in use. Each device must have a unique device ID.

Internal SCSI drives use jumper blocks to set both termination and device ID values. External drives and devices might use a dial, slider, or pushbutton to set termination and device ID (see Figure 3.11). High-speed external SCSI devices often use an external terminator that plugs into the unused SCSI port.

If the new drive has been connected to a SCSI port that has no other devices attached to it

• The port might be disabled or have a conflict. Open the Device Manager to check the port's status. If the port is disabled, enable it. Correct any problems indicated by Device Manager. See "Using Device Manager," p. 480.

• You must terminate the new device.

• Verify that an external drive is turned on after you connect it to the system; the drive must be turned on before the computer is turned on to enable it to be detected.

Figure 3.11 A typical SCSI internal drive (top) and external scanner (bottom) demonstrating the types of SCSI cable connections, device ID and termination options on different SCSI devices.

If the drive is connected to an external port

• You must use the correct type of cable. Some SCSI devices use cables with the same DB25M connector used for parallel-port switchboxes and Direct Parallel/Cable Connection (LapLink/Interlink) cables, but the cables are not the same. Use a cable made especially for SCSI.

• Make sure the last device in the daisy-chain is terminated. If you attach the SCSI drive after other existing devices, turn off the termination on the last device present before the new drive is added, connect the new drive, and enable termination on the new drive.

• Make sure the new drive and all other SCSI devices are powered up before you start the computer.

After the hard drive is installed and the SCSI host adapter has detected it, you must use a utility supplied with the SCSI host adapter vendor to perform a low-level format on the drive before you can prepare it for use with Windows.

Determining That the SCSI Drive Is Defective

If other SCSI devices on the same daisy-chain are working correctly, and you've checked all the settings (device ID, termination, power, cables) discussed above, your drive is probably defective. Contact the vendor for repair or replacement.

However, if no device works when connected to your SCSI card, regardless of configuration, the SCSI host adapter card is probably defective and should be repaired or replaced.

Troubleshooting a PC Card Drive

PC Cards (also called PCMCIA cards) provide a wide variety of I/O services to portable computers, including providing a drive interface. However, if any of the following are true, your PC Card-interfaced drives won't work properly:

• PC Card is not completely inserted

• PC Card handlers are not installed in the operating system

• The drive attached to the PC Card is not connected to a power source (if it requires external power) or turned on—While most PC Card devices are powered by the PC Card slot, some devices that can be connected to multiple interface types have on/off switches.

If a PC Card is not completely inserted into the PC Card slot, you need to eject it and slide it in all the way. When it is installed, you should see a PC Card icon appear in the Windows system tray, by default, at the bottom of the screen (next to the clock). Windows XP refers to this icon as the Safely Remove Hardware icon.

If you have fully inserted a PC Card into the PC Card slot, and it is not recognized, there are three possible reasons:

• Windows cannot locate drivers for the PC Card

• The PC Card configuration software used by Windows is not loaded

• The PC Card configuration software used by Windows might have a problem

Open the Device Manager and verify that the PC Card or CardBus (PCMCIA) controller is available and working properly. If the controller is visible, but doesn't report any problems, look for the icon for the device you installed. If it was recognized as a PC Card or CardBus device, it will be listed in the PCMCIA category in Device Manager. If you don't see the device listed in the PCMCIA category, it might be listed in the Other Devices category (see Figure 3.12). Open the device's properties sheet to verify that the device is installed in the PCMCIA slot. Follow the troubleshooting instructions listed; normally, you will need to install the correct driver for the device to enable Windows to recognize it.

See "Using the Device Manager," p. 480 for details on troubleshooting hardware devices.

See "Hardware Resources," p. 117 for details on how IRQs, I/O port addresses, and memory addresses are used by hardware.

If the controller is not visible, run Add New Hardware and install or troubleshoot it. A PC Card or CardBus controller is a very resource-hungry beast, using an IRQ, several memory ranges, and several I/O port address ranges. However, it should work correctly unless its drivers have been corrupted or another device is using one or more of the same memory or I/O port address ranges. If the controller is displayed, but has problems, use the status listed in the controller's properties sheet to determine the problem and solve it.

Figure 3.12 An unrecognized device installed in a PCMCIA (PC Card or CardBus) slot.

For more information on using the Solution button shown in Figure 3.12, see "Solving Resource Conflicts with Device Manager," p. 481.

If the drive attached to the PC Card is not connected to a power source (if it has one) or turned on, the card might be recognized, but the drive will not work. Turn the drive on. If the drive won't power up, check the power connection to the drive.

Determining That the PC Card Drive Is Defective

A PC Card drive is a more complex device than other drives because the drive itself may be working but the PC Card interface might not work correctly. If the PC Card drive can be connected to another type of interface and the drive works correctly, the PC Card interface is probably defective and should be replaced. If the PC Card slot in the computer works with other types of PC Card devices (modems, network adapters, I/O ports, and so forth), but won't work with your PC Card drive, the drive (or its device drivers) is clearly at fault.

If you have loaded the correct drivers for your PC Card drive on a system with a working PC Card slot and the drive can't be detected after trying all the steps listed above, contact the vendor for help. The drive might be defective and need to be serviced or replaced.

Troubleshooting a Parallel Port Drive

Before the advent of USB and IEEE-1394 ports, parallel ports were commonly used for external drive interfacing with both desktop and notebook computers; they are still useful for situations in which you want to share a drive among systems that lack USB or IEEE-1394 ports. However, if any of the following are true, you won't be able to detect or use a parallel-port drive:

• You haven't run the configuration software supplied with the drive

• Parallel port hardware resources conflict with another device

• Incorrect mode setting for the parallel port

• Drive is not powered on

• Correct drivers are not installed

• Drive is not connected to the computer

Troubleshooting Drive Configuration Software

Parallel ports were originally designed to work with parallel printers; all other uses require driver software. In addition to driver software, some parallel-port drives (such as the Iomega Zip) require the user to run configuration software to detect the parallel port and the drive and configure the connection. You might need to install this software before you connect the drive; see the drive's documentation for details.

If your parallel port drive is not visible in My Computer or Windows Explorer, you should rerun the configuration software program, even if you've run it before. If the configuration program can't locate the drive, check the other items listed below to locate the source of your problem.

Troubleshooting Hardware Conflicts with Parallel Ports

If you find that your parallel port was already configured properly, or if changing it to the proper setting hasn't alleviated the problem, then it's time to look elsewhere for the cause. To see if there are hardware conflicts or driver problems with the parallel port, open the Device Manager.

See "Using the Device Manager," p. 480, for details.

Parallel ports built into the motherboard are usually configured as ISA devices, which means they cannot share IRQ settings with other devices. Parallel ports on ISA cards are also ISA devices. Parallel ports on PCI cards are PnP devices that can share IRQ settings with other cards.

Troubleshooting Parallel Port Mode Settings

While Windows can print to many parallel port printers regardless of the port settings, most parallel port drives require that the port be configured as an EPP or ECP port and not have any hardware resource conflicts with other devices.

For details, see "Using the Device Manager," p. 480, for details.

For more details about accessing and using the system BIOS setup program, see "BIOS Setup," p. 104.

To check or change the parallel port mode and hardware resource settings currently in use for a built-in parallel port

1. Restart the computer.

2. Start the system BIOS setup program.

3. Display the menu that contains the parallel (LPT) port settings (see Figure 3.13).

Figure 3.13 A typical computer's BIOS configuration screen for built-in parallel ports; the NORMAL setting shown here doesn't support bi-directional devices such as drives and should be changed to bi-directional, EPP, or ECP as recommended by the drive vendor.

4. Compare the current parallel port setting to the setting recommended for the drive. If the current parallel port setting is not configured properly for the drive, change it to a suitable setting. This setting most likely should be EPP or ECP, but check your drive's manual to be sure.

5. If you need to change hardware resource settings such as IRQ, DMA, or I/O port address to avoid conflicts with another device (as displayed by Device Manager), select non-conflicting settings.

6. Save any changes you made to the BIOS configuration, and restart the computer.

Troubleshooting Add-On Parallel Port Configuration Issues

If you have installed an add-on parallel port card (see Figure 3.14), you need to configure the card using its own setup features. If the card uses an ISA expansion slot, it might use jumper blocks or a software setup program to configure card settings such as parallel port mode or hardware resource settings. PCI parallel port cards are configured with Windows's Plug and Play technology.

See "PCI Configuration," p. 112 for more about the differences between PCI and ISA slots and resource usage.

If you are using an add-on parallel port card, see the card's documentation for details on how to configure it.

Figure 3.14 A typical computer with a built-in parallel port and an add-on parallel port card.

Troubleshooting Parallel Port Cabling and Power Issues

Because many different types of cabling with different pinouts are used for parallel-port devices, make sure you use the cable provided by the vendor for your parallel-port drive. If the cable is not long enough, you might need to extend the cable with a straight-through cable, such as the type sold for computer to parallel switchbox connections. Don't use a cable made for file transfers, as it crosses some wires and omits other wires needed for parallel devices. If the cable has cracks or cuts in the jacket, the signal wires inside might be damaged; order a replacement from the drive vendor.

If you have your computer's parallel port configured as an EPP, ECP, or EPP/ECP port, make sure any extension cable you use corresponds to the IEEE-1284 parallel port standard. Cables that aren't IEEE-1284 compliant might not work because some pins in the cable connector which are needed for fast IEEE-1284 modes aren't used in non-compliant cables.

Be sure you use the power adapter provided with the drive; buy a replacement from the drive vendor instead of looking for a generic replacement. Most power adapters made for drives have non-standard voltage and amperage ratings, and third-party generic replacements won't work and might damage the drive.

Use the thumbscrews on the parallel cable to securely attach the cable to the parallel ports on the drive and the computer. Since the parallel cable is very heavy, pushing the cable into place could cause a poor connection.

As with other external drives, parallel-port drives must be turned on before they can be recognized and used. If the drive's software was installed and the drive was turned on and connected to a properly configured parallel port without any resource conflicts, but the drive can't be recognized, you might need to update the drive's device drivers. Check with the vendor's Web site for updates and details.

Troubleshooting Parallel Port Daisy-Chaining Issues

Because parallel ports were not originally designed to connect to devices other than printers, daisy-chaining a drive and another device other than a printer to a parallel port might not work (normally, a drive plus a printer works with little difficulty).

If you have the drive plugged into another device that is plugged into the parallel port, make sure the other device and the drive are turned on before you turn on the computer. If the drive still won't work, shut down the computer and all devices and plug your drive directly into the parallel port. If the drive works when it's plugged directly into the parallel port, but not when it's connected to the other device, you might not be able to use the two devices on the same port. Try adjusting the mode (EPP, ECP, EPP/ECP) and connect the other device to the drive to see if reversing the order of devices in the daisy-chain will work correctly.

Determining That a Parallel Port Drive Is Defective

If you have checked parallel-port settings and hardware resources, verified proper connection of cables and power, and adjusted the connection order of the drive and any other parallel-port, and the drive doesn't work, but a printer or other parallel-port devices are working, the drive is probably defective.

However, if no devices (solely or in a daisy-chain) will work with the parallel port, the port itself is defective. Contact your vendor for service.