Canon 70D does not focus anymore when button half pressed

[XANDERIX]

My Canon EOS 70D camera does not respond when I want to take pictures when the lens is set in autofocus (AF) mode. Normally it would focus when I press the button half and take a picture when pressed fully. Unfortunately, it doesn’t focus anymore and it doesn't want to take the picture either. However, when I switch the button on the lens from AF to MF, then it does function normally.

I have tried:

1. Update/reinstall the firmware (1.1.3) - no change
2. Use different lenses (all Canon) - no change
3. Switch between viewfinder and screen - no change 
4. Charge the battery fully - no change
5. Use P, Av, M, etc. - no change
6. Change the focus mode between ONESHOT/AI FOCUS and AI SERVO - no change with the fist two, but in AI SERVO it does take a picture, but it still won't not focus

Does anyone have suggestions on what could cause this malfunctioning and are there solutions?

Thanks a lot!

[shadowsports]

Greetings,

Have you reset the cameras Main and Custom settings and tested again without customization?

What happens if you set shooting mode to Av, set an aperture value of f18 or more and press the Depth of Field preview button?

If you aren't getting a response here after reset and testing with different lenses, the camera should be inspected by Canon.  Some 70D's were affected by a PCB defect.  See this article:

Canon Support | Service Notice: EOS 70D: Error 70 or Error 80 | Canon U.S.A., Inc.

The error was Err70 or 80 specifically, but its possible other unexpected behaviors might occur.  Check the article as only a certain number of serial numbers were affected.  Your issue could be completely unrelated.