Communication error #04402 (MMU)

This article is also available in following languages: 

What happened?

There were frequent errors detected in the communication between the printer and the MMU unit. The digital communication “messages” between the printer and the MMU unit are checked using the CRC function and verified for reception. If these checks fail multiple times in a row, this error is shown.

How to fix it?

Check the following:

• Make sure the MMU unit is present on the printer. If not, either connect the MMU unit back or turn the MMU off either by selecting Disable MMU or in the printer’s menu.

• Verify all the cables are in good condition and the connections are stable.
• Make sure your MMU3 unit is correctly assembled with the PD-board addon attached.
• Make sure you are using the correct up-to-date firmware for both the printer and the MMU unit
• Verify no source of interference is close to the data cables.
• Do not use extending cables.