The CD-ROM has a different sound when it reads the disk

When using a computer optical drive to read a disk, the CD-ROM drive has a "tweeted" sound.

The above fault is a lot of users have encountered, is due to the CD ROM drive reading capacity or poor quality, CD-ROM indicates that there is serious dirt. In this case, the optical drive can check the format of the disc and the existence of the disc, but when reading the data, the laser head will read the data as much as possible under the action of the servo circuit. This time if the laser head up the position is too large, and because the quality of the disc is poor, indicating uneven, the disc high-speed work is not in a plane, the laser head move focus will touch the disc, continue to contact with the disc will produce "tweeted" voice.

If the purchase of pirated discs, even if the disk is very new, but the data trajectory is lighter, not easy to read. When the disc is removed, there will be a lot more scratches, which is why pirated discs are prone to scratch. Serious, because the CD-ROM high-speed work, will also produce fried disk phenomenon, resulting in optical drive damage and can not continue to work.