# Canon 7D Error 40



## Rye (May 5, 2017)

Today I went to turn on my 7D and got a blank LCD. Reached in my bag for a fresh battery, popped it in, got an "Error 40".  I tried two other charged batteries and got the same result. Took off and re-mounted the lens, took out and put back in the CF card, turned the camera back on and it worked fine after that. I'm also finding that if I leave a dead battery or a battery that's low on charge in it then put in a fresh battery the camera forces me to reset the date and time as soon as I turn it back on. 

Anyone else have this experience? I was thinking maybe a weak or dead internal battery?


----------



## tecboy (May 6, 2017)

You may want to contact Canon.  There are plenty of people posted on other forums who have similar problem.

I'm not sure this video would help.


----------

