Skip to main content

The Canon EOS 7D was Canon's first high end professional camera with an APS-C crop sensor.

49 Questions View all

ERR MESSAGE 40 Power Source Malfunction

I was shooting a birthday party the other night and the camera just stopped working. I first noticed the battery gage level was going up then all the way down. I looked up ERR 40 and it said on a site it's a power source malfunction. Is there any way I can fix it or does it need to be returned?


Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

1 Answer

Chosen Solution


Here's some basic troubleshooting information from Canon:

""Err 40" indicates that a malfuction related to the power source has been detected. Please follow these steps to attempt to resolve the error:

- Power down the camera.

- Remove the lens, battery and memory card.

- Let the camera sit for 10 minutes.

- Use a soft microfiber cloth to clean the contacts on the battery and inside the battery compartment.

- Reinstall the battery.

- Power the camera on."

If that doesn't work it might be more serious component issue.

Was this answer helpful?

Score 3
Add a comment

Add your answer

dmsteach will be eternally grateful.
View Statistics:

Past 24 Hours: 1

Past 7 Days: 2

Past 30 Days: 6

All Time: 1,236