Hi,

We just bought our 3rd t3i and after putting on the LCDVF frame the screen turns off when you attach the viewfinder to it. It only seems to turn off when the lCD is snapped into the body. If it's pen away from the body it stays on. Our other t3is, our 60ds, our t2is all works fine with the viewfinder attached. It's just this one camera. Everything else seems to work fine. The newer t3i that doesn't work is firmware 1.0.1 and the older ones that do work are just 1.0.0.

I thought the new cameras didn't have a sensor to turn off the LCD but I can't explain what the problem is here. Ive been thru all the menu settings and the manual and I just can't figure it out. Hopefully some has seen this before and it's just a setting I'm missing.

Any help would be greatly appreciated.

Thanks,
Scott

Is the edge of the unit's cup resting against the button that activates/deactivates Live View?

No, definitely not. The LCDVF attaches by sticking a metal frame on the LCD then the viewfinder has magnets in it that attach it to the camera. The problem is totally intermittent so I'm sending the camera back to B&H for a new one.

I just checked with my 600D to confirm that the screen does indeed switch off when you swivel it round so it is tucked away facing the body. There is obviously a switch in the hinge or sensor of some sort that checks the orientation of the screen. I suspect that this is what is playing up on this problematic camera.

That's the best explanation I've heard so far. The sensor must be magnetic though (maybe?). The screen stays on just fine when seated against the body, it's when the LCDVF is snapped onto the screen that it shuts off.