Upgrading and Repairing PCs

Troubleshooting Sound Card Problems

To operate, an audio adapter needs hardware resources, such as IRQ numbers, a base I/O address, and DMA channels that don't conflict with other devices. Most adapters come preconfigured to use the standard Sound Blaster resources that have come to be associated with audio adapters. However, problems occasionally arise even with Plug and Play adapters. Troubleshooting might mean that you have to change the settings used by your system BIOS for PnP devices, move the sound card to another slot, or even reconfigure the other devices in your computer. No one said life was fair.

Hardware (Resource) Conflicts

The most common problem for audio adapters (particularly if you still use ISA cards) is that they might conflict with other devices installed in your PC. You might notice that your audio adapter simply doesn't work (no sound effects or music), repeats the same sounds over and over, or causes your PC to freeze. This situation is called a device, or hardware, conflict. What are they fighting over? Mainly the same bus signal lines or channels (called resources) used for talking to your PC. The sources of conflict in audio adapter installations are generally threefold:

• Interrupt Requests (IRQs). Hardware devices use IRQs to "interrupt" your PC's CPU and get its attention. PCI cards can share IRQs, but ISA cards and onboard legacy ports such as serial, parallel, and PS/2 mouse ports can't.

• Direct Memory Access (DMA) channels. DMA channels move information directly to your PC's memory, bypassing the system processor. DMA channels enable sound to play while your PC is doing other work. ISA sound cards and PCI sound cards emulating the Sound Blaster standard require DMA settings; PCI sound cards running in native mode don't use DMA channels.

• Input/output (I/O) port addresses. Your PC uses I/O port addresses to channel information between the hardware devices on your audio adapter and PC. The addresses usually mentioned in a sound card manual are the starting or base addresses. An audio adapter has several devices on it, and each one uses a range of addresses starting with a particular base address.

Most audio adapters include installation software that analyzes your PC and attempts to notify you if any of the standard settings are in use by other devices. The Windows Device Manager (accessed from the System Control Panel) can also help you to resolve conflicts. Although these detection routines can be fairly reliable, unless a device is operating during the analysis, it might not always be detectable.

Some of the newer PCI-based sound cards and Intel chipset motherboards might not properly support ISA-type I/O addresses used by Sound Blaster–compatible software to communicate with the card. If you have problems getting older games to work with your system, see the tips listed earlier for emulation methods, check with your sound card and system board/computer supplier for help, and check with the game developer for possible patches and workarounds.

Table 16.4 shows the default resources used by the components on a typical Sound Blaster 16 card, which uses a 16-bit ISA slot. Other sound cards used to emulate a Sound Blaster typically use these same settings.

Table 16.4. Default Sound Blaster Resource Assignments

Device	Interrupt	I/O Ports	16-Bit DMA	8-Bit DMA
Audio	IRQ 5	220h–233h	DMA 5	DMA 1
MIDI Port	—	330h–331h	—	—
FM Synthesizer	—	388h–38Bh	—	—
Game Port	—	200h–207h	—	—

All these resources are used by a single sound card in your system. No wonder so many people have had conflicts and problems with audio adapter installations! In reality, working out these conflicts is not all that hard, as you will see. You can change most of the resources that audio adapters use to alternative settings, if conflicts with other devices occur; even better, you can change the settings of the other device to eliminate the conflicts. Note that some devices on the audio adapter, such as the MIDI port, FM synthesizer, and game port, do not use resources such as IRQs or DMA channels.

Compare the resource settings used by a traditional ISA sound card (refer to Table 16.4) to those used by a typical PCI-based sound card (see Table 16.5).

Table 16.5. Typical Sound Blaster Audigy Resource Assignments

Device	Interrupt	I/O Ports	16-Bit DMA	8-Bit DMA
Audio	IRQ 3	4000–401F	—	—
MIDI Port	(included in above configuration)
FM Synthesizer	(included in above configuration)
Game Port	—	1400–1407	—	—

If you don't need MS-DOS game support, the PCI card uses far fewer resources than the ISA card. However, if you are using MS-DOS games, you will need to set up a number of "virtual" IRQ, I/O port, and DMA port settings for use with those games only.

When using a typical PCI-based sound card's Sound Blaster Legacy settings, you must verify that MS-DOS software using the Sound Blaster is set for the appropriate configuration (see Figure 16.10).

If you are still using MS-DOS games (or even some Windows programs designed for Windows 95 or earlier), I recommend that you install your audio adapter (or configure a notebook computer's built-in sound adapter circuits) to use the default settings whenever possible. This is mainly because of poorly written software that can't work properly with alternative settings, even if they do not cause conflicts. In other words, if you are having a conflict with another type of adapter, modify the settings of the other device, rather than those of the audio adapter. Take this from experience; otherwise, you will have to explain to your five-year-old why the new Dinosaur program you just installed does not make any sounds! This problem is primarily associated with DOS-based game programs, but some older Windows-based programs have also been incapable of working with alternative hardware settings.

Note Some of the chipsets for "legacy-free" systems, such as the Intel 810 and 820 chipsets, don't decode addresses below 1000h to the PCI bus. All the Sound Blaster I/O port addresses are well below 1000h, and thus sound card manufacturers will need to adjust driver software or use TSR programs to reroute calls to these I/O port addresses by software to the correct I/O port addresses. This design choice is not a problem for typical Windows software that uses sound, but it can cause legacy (DOS-based) applications to fail.

Resolving Resource Conflicts

Resource conflicts are quite rare with current PCI-based audio adapters, thanks to their support of Windows Plug and Play technology and the PCI IRQ sharing/steering feature supported by Windows 95 OSR 2.x and above and recent chipsets.

However, if you are still using the original version of Windows 95 or an ISA-based audio adapter (including some motherboard-based chipsets on older systems), you can have significant problems because of IRQ and DMA conflicts with other devices.

See Upgrading and Repairing PCs, 12th Edition on the DVD-ROM for details.

Other Sound Card Problems

Like the common cold, audio adapter problems have common symptoms. Use the following sections to diagnose your problem.

No Sound

If you don't hear anything from your audio adapter, consider these solutions:

• Make sure the audio adapter is set to use all default resources and that all other devices using these resources have been either reconfigured or removed. Use the Device Manager to determine this information.

• Are the speakers connected? Check that the speakers are plugged into the sound card's stereo line-out or speaker jack (not the line-in or microphone jack).

• Are the speakers receiving power? Check that the power "brick" or power cord is plugged in securely.

• Are the speakers stereo? Check that the plug inserted into the jack is a stereo plug, not mono.

• Are the mixer settings correct? Many audio adapters include a sound mixer application. The mixer controls the volume settings for various sound devices, such as the microphone or the CD player. There might be separate controls for both recording and playback. Increase the master volume or speaker volume when you are in the play mode.

  If the Mute option is selected in your sound mixer software, you won't hear anything. Depending on the speaker type and sound source type, you might need to switch from analog to digital sound for some types of sound output. Make sure that the correct digital audio volume controls are enabled in your audio device's mixer control.

• Use your audio adapter's setup or diagnostic software to test and adjust the volume of the adapter. Such software usually includes sample sounds used to test the adapter.

• Turn off your computer for 1 minute and then turn it back on. A hard reset (as opposed to pressing the Reset button or pressing Ctrl+Alt+Delete) might clear the problem.

• If your computer game lacks sound, check that it is designed to work with your audio adapter. For example, some legacy and early Windows games might require the exact settings of IRQ 7 (or IRQ 5), DMA 1, and I/O address 220 to be Sound Blaster compatible. You also might need to load DOS drivers to enable some recent sound cards to work with DOS games.

One-Sided Sound

If you hear sound coming from only one speaker, check out these possible causes:

• Are you using a mono plug in the stereo jack? A common mistake is to use a mono plug in the sound card's speaker or stereo-out jacks. Seen from the side, a stereo connector has two darker stripes. A mono connector has only one stripe.

• If you're using amplified speakers, are they powered on? Check the strength of the batteries or the AC adapter's connection to the electrical outlet. If each speaker is powered separately, be sure that both have working batteries.

• Are the speakers wired correctly? When possible, use keyed and color-coded connectors to avoid mistakes.

• Is the audio adapter driver loaded? Some sound cards provide only left-channel sound if the driver is not loaded correctly. Rerun your adapter's setup software or reinstall it in the operating system.

• Are both speakers set to the same volume? Some speakers use separate volume controls on each speaker. Balance them for best results. Separate speaker volume controls can be an advantage if one speaker must be farther away from the user than the other.

• Is the speaker jack loose? If you find that plugging your speaker into the jack properly doesn't produce sound but pulling the plug half-way out or "jimmying" it around in its hole can temporarily correct the problem, you're on the road to a speaker jack failure. There's no easy solution; buy a new adapter or whip out your soldering iron and spend a lot more time on the test bench than most audio adapters are worth. To avoid damage to the speaker jack, be sure you insert the plug straight in, not at an angle.

Volume Is Low

If you can barely hear your sound card, try these solutions:

• Are the speakers plugged into the proper jack? Speakers require a higher level of drive signal than headphones. Again, adjust the volume level in your mixer application.

• Are the mixer settings too low? Again, adjust the volume level in your mixer application. If your mixer lets you choose between speakers and headphones, be sure to select the correct speaker configuration.

• Is the initial volume too low? If your audio adapter has an external thumbwheel volume control located on the card bracket, check to ensure that it is not turned down too low.

• Are the speakers too weak? Some speakers might need more power than your audio adapter can produce. Try other speakers or put a stereo amplifier between your sound card and speakers.

Scratchy Sound

Scratchy or static-filled sound can be caused by several problems. Improving the sound can be as simple as rearranging your hardware components. The following list suggests possible solutions to the problem of scratchy sound:

• Is your audio adapter near other expansion cards? The adapter might be picking up electrical interference from other expansion cards inside the PC. Move the audio card to an expansion slot as far away as possible from other cards.

• An ISA-based audio adapter requires a lot of CPU attention. Frequent hard disk access can cause dropouts due to the CPUs switching between managing the sound card and the hard drive.

• Are your speakers too close to your monitor? The speakers can pick up electrical noise from your monitor. Move them farther away. Subwoofers should never be placed near the monitor because their powerful magnets can interfere with the picture. They should be on the floor to maximize low-frequency transmission.

• Are you experiencing compatibility problems between particular games and your sound card? If you notice sound problems such as stuttering voices and static on some games but not others, check with the game vendor for a software patch or with the sound card vendor for updated drivers. If the game uses DirectX, run the DXDIAG diagnostics program (select Start, Run; type DXDIAG; and click OK) and click the Sound tab. Adjust the slider for Hardware Sound Acceleration Level down one notch from Full (the default) to Standard, click Save All Information, and exit. Retry the game. If the problem persists, adjust the Hardware Sound Acceleration Level to Basic. If other games have performance problems after you adjust the Hardware Sound Acceleration Level, be sure to reset it to Full before playing those games.

Your Computer Won't Start

If your computer won't start at all, you might not have inserted the audio adapter completely into its slot. Turn off the PC and then press firmly on the card until it is seated correctly.

If you can't start your computer after installing a new sound card and its drivers, you can use the Windows "bootlog" feature to record every event during startup; this file records which hardware drivers are loaded during startup and indicates whether the file loaded successfully, didn't load successfully, or froze the computer. See the documentation for your version of Windows for details on how to create a bootlog when necessary.

Parity Errors or Other Lockups

Your computer might display a memory parity error message or simply crash. This is usually caused by resource conflicts in one of the following areas:

• IRQ

• DMA

• I/O ports

If other devices in your system are using the same resources as your audio adapter, crashes, lockups, or parity errors can result. You must ensure that multiple devices in your system do not share these resources.

Advanced Features

If you are having problems playing DVD audio, playing MP3 files, or using SPDIF connections, make sure that

• You have enabled the hardware resources on the sound card.

• You are using the correct playback program.

• Your mixer has the correct volume control setting for the device.

• Your cabling is correct for the device.

Other Problems

Sometimes sound problems can be difficult to solve. Due to quirks and problems with the way DMA is implemented in some motherboard chipsets, problems interacting with certain cards or drivers can occur. Sometimes altering the Chipset Setup options in your CMOS settings can resolve problems. These types of problems can take a lot of trial and error to solve.

The PC standard is based loosely on the cooperation among a handful of companies. Something as simple as one vendor's BIOS or motherboard design can make the standard nonstandard.

A good way to solve problems of all types with Plug and Play cards, a PnP BIOS, and a PnP operating system (Windows 9x/Me/2000/XP) is to use the Device Manager to remove the sound card, restart the system, and allow the card's components to be redetected. This installs a "fresh" copy of the software and reinserts Registry entries.

If you are using a motherboard with a VIA chipset, be sure to download and install the latest versions of VIA drivers.