Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 807)

4.
Remove the lens and clean the sensor.
5.
End the cleaning.
Set the power switch to < >.
Note
Using the household power outlet accessories (sold separately) is recommended.
Caution
While cleaning the sensor, never do any of the following. If the power is cut
off, the shutter will close and the reflex mirror will go back down. These may
result in damaging the image sensor, shutter curtains, and reflex mirror.
• Setting the power switch to < >.
• Removing or inserting the battery.
Do not move the reflex mirror with your hand. This may damage the mirror.
The surface of the image sensor is extremely delicate. Clean the sensor with care.
Use a plain blower without any brush attached. A brush can scratch the sensor.
Do not insert the blower tip inside the camera beyond the lens mount. If the power
is turned off, the shutter will close and the shutter curtains or reflex mirror may get
damaged.
Never use pressurized air or gas to clean the sensor. Pressurized air may damage
the sensor, and sprayed gas may freeze on the sensor and scratch it.
If the battery level becomes low while cleaning the sensor, the beeper will sound as
a warning. Stop cleaning the sensor.
If a smudge that cannot be removed with a blower remains, having the sensor
cleaned by a Canon Service Center is recommended.
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