Top Page > Operating Instructions > Troubleshooting > Precautions for Removing Jammed Paper / Replacing Consumables > When Replacing Consumables
For the location of the sensors in the machine and replacement units, see the following illustrations.
Main unit
![machine illustration](../image/dul710.gif)
1. When replacing the drum unit
![machine illustration](../image/dul702.gif)
2. When replacing the fusing unit
![machine illustration](../image/dul703.gif)
3. When replacing the transfer unit
![machine illustration](../image/dul704.gif)
4. When replacing the waste toner bottle
![machine illustration](../image/dul705.gif)
Drum unit
![machine illustration](../image/dul707.gif)
Fusing unit
![machine illustration](../image/dul708.gif)
Transfer unit
![machine illustration](../image/dul709.gif)