Scanners make loud noises for two main reasons.
The first is simply due to the design of the scanner. Many flatbed and document scanners contain components with moving parts, like motors and belts, which can create a loud noise when in use. The louder the noise, the higher the running speed of the scanner. The second reason could be mechanical issues such as a loose or damaged belt, worn out roller bearings and motors, or other parts that could cause the scanner to vibrate, which in turn would make a loud noise.
In some cases, loud noises can indicate an issue with the way the scanner’s components are working together. If the noise is coming from a sheet-fed scanner, it could be caused by a misaligned paper feeder tray or debris in the scanner bed. If the noise is coming from a flatbed scanner, it could be caused by a misaligned scanning head or a loose lens assembly.
If your scanner has been making a loud noise, it is important to have it checked and serviced by an experienced technician. This will help you identify the cause of the noise, so the proper repairs can be made and the scanner can run more efficiently and quietly.