The following information will help you detect any problems related to the Encoder Disk:

Horizontal and periodic white lines, all of them with the same width depending on the failure mode. This is a clear indication that the Encoder Disk is damaged.

System Error 56:10 - This means that you have to replace the Drive Roller Encoder Sensor. But, if the problem persists, replace the Encoder Disk Assembly.

System Error 81:01 - This means a Paper-Axis shutdown. If this error code appeared but was NOT caused by a paper jam, then perform the Paper Advance Test. See Paper Advance Test. If the Paper Advance Test fails during the third test, the Front Panel will display the following message:

In this case, you should replace the Drive Roller Encoder Sensor. But, if the problem persists, replace the Encoder Disk Assembly.

NOTE: In order to remove the Encoder Disk, you must first remove the Drive Roller. Be very careful when assembling the Axle Spring because you could damage the Encoder Disk. Check that no air bubbles are trapped between the Encoder Disk and the hub once it is installed.