Brother HL-3400CN Series - Manual (Page 175)

USER’S GUIDE
5-18
Fusing Unit
Fusing Unit
When the following message appears on the LCD panel, you must replace
the Fusing Unit:
REPLACE FUSER
Warning
The Fusing Unit and the parts around it are HOT!. Be sure to wait
until the Fusing Unit has cooled down sufficiently before replacing
the Fusing Unit.
If you touch the HOT parts, you might get injured.
Warning
After replacing the Fusing Unit, wait for approximately 30 minutes
before printing after the new unit is installed to allow the fusing oil to
circulate.
Replacing the Fusing Unit
1. Press the Power button to turn off the printer. Unplug the printer.
To avoid injury, wait until the printer has cooled down sufficiently
before replacing the Fusing Unit.
2. Open the Top Cover.
3. Unscrew the two long screws as shown to release the Fusing unit from
the printer.
Fig. 5-20 Remove screws