Optical media problemsOptical media problems include media quality problems and unreported write problems.
Media quality problemsProblems that you may experience with media quality include the following problems:
- The media is of low quality.
We recommend that you use high quality optical media.
- Rewriteable media may have been used too many times.
You can write to rewritable optical discs only a certain number of times before you must fully erase the disc.
- The media is old.
Optical media may degrade over time. This degradation may occur faster if the media is exposed to direct sunlight or if the media is stored in a humid location.
Unreported write problemsUnreported write problems include the following problems:
- The write operation is only marginally successful. In this case, you experience a symptom that resembles the following symptom:
The media write operation is successful, and the verification operation is successful. This indicates that the drive that performed the write operation can successfully read the media. However, when you insert the media into another drive such as a read-only drive, the media has errors.
This problem occurs because DVD writers and CD writers have more tolerance for errors in the writing process than in the reading process. Additionally, the reader drive may have higher-quality lenses to help focus the laser.
Note You may experience this problem more frequently when you use the written media in a mobile computer. The optical drive in a mobile computer is constrained by space issues. Therefore, a mobile computer optical drive may have more difficulty reading data that is written at the edge of the tolerances.
- The write speed is too fast. This is a common problem. To better understand this problem, consider the following issues that may be exacerbated by a fast write speed:
- Focus errors
Recordable discs are mass-produced. This implies that a small amount of variance may occur in the weight of the disc around the center hole. When the disc spins, this weight difference may cause the disc to wobble up and down slightly.
Additionally, the center hole may be slightly off-center. If this occurs, the radius of the area that is to be written to may vary slightly during the disc's rotation.
Both of these issues are well-known. Optical devices are designed to handle this behavior. However, this behavior is more pronounced at higher speeds.
- Heating errors
To write to rewritable media, the laser must heat the substrate a certain amount. This is because the media changes the amount of light that it reflects based on how the media cools. This is to allow for a transition between reflective and less reflective parts of the media.
When you write to a rewritable disc at very high speeds, the tolerance for focus errors is decreased. Therefore, the laser may not heat the substrate as accurately as it can when the disc spins more slowly.
- Focus errors
- A buffer underrun occurs. This problem is less common because all newer optical writers include buffer underrun protection.
Typically, buffer underrun protection is turned on by default. However, if a buffer underrun occurs, a small missed spot occurs in the written track. This may cause some drives to experience difficulty reading the next sector.
Optical drive problemsOptical drive problems include optical focus failure, non-optimal ATAPI connections, and outdated firmware.
Optical focus failureThe focusing component of a drive is generally a plastic stabilizer. Over time, this component may fail. This failure may cause focusing problems to occur during read and write operations. Therefore, you may experience random read failures when you use the drive. This issue occurs even if you use the drive to read media that can be read in other drives.
Note The focusing component may wear out more quickly in a high-usage environment.
Non-optimal ATAPI connectionsYou may experience problems if the ATAPI optical drive does not use the optimal cable or jumper settings. Consider the following information:
- Most current ATAPI devices can use a DMA mode that requires an 80-pin cable to maximize signal integrity. We recommend that you use 80-pin cables for all ATAPI devices.
- If the cable is not seated correctly, some of the data that is transferred may be lost. We recommend that you reseat all the cables to the devices. Additionally, you may want to verify that no pins are bent on the device or on the controller to which the cable is connected.
- Optical drives should be explicitly jumpered as "Master" or "Device 0" when they are the only devices that are connected to the cable.
When two drives are connected to the cable, you should configure one drive as the "Master" or "Device 0" drive and one drive as the "Subordinate" or "Device 1" drive. We recommend that you do not use the "Cable Select" jumper setting.
Outdated firmwareOptical drives contain firmware. We recommend that you determine whether an update for the firmware exists for the drive. For more information about how to do this, visit the following Microsoft Web site:
File problemsProblems may occur if the file that you wrote to the optical media is damaged. To test an .iso file, you can use a virtualization program such as Microsoft Virtual PC 2004 to mount the file in a virtual drive.
- Use a known brand of optical media that is certified for use by the drive manufacturer.
- Use a write-only media, such as DVD -R or DVD +R media.
- Store media in a cool, dark location.
- Write to the optical media by using the lowest write speed that is available.
- Verify that the buffer underrun feature is enabled.
- Examine the log files from the CD or DVD burning program to determine whether any error messages are generated.
- Verify that the jumpers on all drives are set correctly.
- For ATAPI drives, verify that you have an 80-pin Ultra DMA 100/133 cable.
- Verify that the drive has the latest firmware installed.
- Reseat all the drive cables.
Artikkel-ID: 929460 – Forrige gjennomgang: 22. okt. 2008 – Revisjon: 1