EOS70d- Can you Help? Black viewfinder screen. No shutter actuation.. No takey pics...

[vrphotography]

I handed my 70d over to my sister to take a shot and when she took it from me an error message flashed and it pretty much quit working. I'm hoping she just pressed some menu item or button by mistake! The msg flashed so quick there was no time to make note what it said. I was given back a camera with a black screen on the back; so now I can't navigate through any menus to find out what happened. There is also no shutter actuation when shutter button is pressed. I've changed out lenses. I've charged battery. Nothing. However, on the top nav window I can see I have a full battery, and can nav thru all the settings available, in both video and camera mode. So, I at least know the camera is alive to some extent. I've searched but cant find any subject covering this. Any ideas?? Here's a few photos of said camera. Also, dont know if my mirror is locked...could that make my camera behave like this? Thanks for any help. I miss my baby.

[kvbarkley]

Have you tried pressing the info button?

[vrphotography]

Yes- tried that. No matter which button I push, nothing illuminates on the backscreen. Nor on the internal viewfinder menu. Only the top external LCD do I find any similance of life. And that doesnt access menu.

[kvbarkley]

Have you tried hooking up an HDMI cable?

Have you tried reseating or removing the eyecup? The eye sensor might be blocked.

[ScottyP]

Toggle the switch that surrounds the START/STOP button on the back.  

[shadowsports]

Afraid this is going to be another controller board failure 

[ScottyP]

1.) Try hitting info repeatedly. It cycles through settings. 

2.) There is on most models a sensor that knows when your face is pressed up to the back of the camera, and it turns the LCD off when the camera is on your face. The sensor can become blocked by dirt or makeup, or by the eyecup sliding up a couple of millimeters and blocking the sensor. In both cases the sensor is fooled into thinking your face is pressed onto the camera and it turns the LCD off. Try removing the eyecup and wiping the area clean between the eyecup and the hot shoe. 

[vrphotography]

Appreciate all the ideas, thanks!!

Ok, so I've toggled the camera/vid selector around the start/stop= nothing

Tapped the info button, repeatedly, nothing.

I removed and cleaned around the eye cup (didnt see the sensor)... but even if that sensor was defective, that shouldnt stop the shutter from firing. It doesnt disengage the shutter when your face is pressed against the camera, under normal circumstances.

I havent hooked up an hdmi from camera to computer yet, but am not sure what to do when i do.

I've only ever used that connection to transfer images. Will that allow me to access other camera functions? 

What should i be looking for? Thanks.

[ScottyP]

You're going to have to hypnotize your sister so she can remember what switch she flipped when you handed her the camera. 

[RobertTheFat]

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@ScottyPwrote:

You're going to have to hypnotize your sister so she can remember what switch she flipped when you handed her the camera. 

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My guess is that it was the "On" switch that did it. The 70D is known to have a component on its circuit board that is to prone to failure when the camera overheats. Such failures commonly manifest themselves the next time power is applied, because suddenly applying power is one of the most stressful actions that an electronic component has to endure. If the component was weakened by overheating, it's likely to fail the next time the camera is turned on.