problem with new(ish) 80D and 400mm

[mitchmcc]

I bought a new outfit in May, including an 80D, a 1.4TC, and 400mm II.   I have been using it quite a bit, and never saw any problems until the other day.

I turned it on, and was trying to set the ISO and nothing was happening.  Same for trying to set the drive, etc.   When I looked through the viewfinder, it was black.    I could not for the life of me think of what was going on.

In trying to debug it, I did notice one thing.   When I re-seated the entire lens + TC at the body interface, everything started working.

I need to do more testing to see if this happens again, but I wanted to ask if anyone ever heard of such behavior, and what it might mean.

Thanks,

Mitch

[mitchmcc]

FWIW, the lens + TC was already mounted, and had been previously used with no issues. Unless I hit some other button, I do not think that the lens mounts were touched.

[ebiggs1]

Reset it.