• The temperature of the fuser unit does not rise to a specified temperature within the specified time.
• The fuser unit is too hot.

Please follow the steps below to solve the problem:

1. Turn the machine's power switch off, wait a few seconds, and then turn it on again.
2. Leave the machine for 15 minutes with the power on. 
3. If the error still remains, please contact Brother Customer Service from "Contact Us" or call your dealer and report the error status, Fuser Error or Self-Diagnostic.