Canon 5D Mark IV randomly stops working

[SMPhotography20]

Hello, 

I have had my 5d mark IV for a few months now and i have noticed some days at sessions i will be mid shoot and the camera will just quit working. the LED screen on top will stay on and all the numbers and settings still appear but the when looking through the viewfinder it is black and when i try to go into live view nothing happens.  i can still press the play button and see images ive taken but the shutter will not fire and i cannot take photos.  I carry a backup 90d body as a fail safe but i dont prefer to use it after the quality of the mark IV.  it will stay locked up like this for around 30 minutes or so.  ive noticed it resolves slightly quicker if i detach the lens and take out the battery.

am i crazy or has this happened to anyone else?

[deebatman316]

What lens are you using also is the viewfinder completely dark when this happens. What accessories do you have attached to the camera. Like a speedlite, battery grip ECT.

[SMPhotography20]

I have a sigma 70-200m 2.8 sport lens as well as a sigma 24-70m 2.8 art and it has happened with both lens. no battery grip or anything else added. just body and lens

[deebatman316]

Do you have a Canon lens to test out. What are the FULL NAMES of the lenses you mentioned above. I've seen cameras lockup like this with older 3rd Party lenses. The mirror will hang up for some unknown reason. Unmounting the lens and removing battery will reset the camera.

[SMPhotography20]

Sigma 24-70mm f/2.8 DG OS HSM Art Lens for Canon EF

Sigma 70-200mm f/2.8 DG OS HSM Sports Lens for Canon EF

[SMPhotography20]

I do not have a canon lens at the moment, that is next on my list to purchase!

[deebatman316]

Do you know anyone that owns an EOS DSLR or SLR camera. You could borrow their lenses. Just make sure they're Canon EF lenses NOT EF-S lenses. They won't physically mount on your camera. The lens could be incompatible. Does the camera display an error code when this happens. If so what error code is present. What firmware version are you currently on. How long have you had this camera.

[SMPhotography20]

It does not give me any sort of error code which i find strange. looks like firmware version 1.3.4

[deebatman316]

The most up to date firmware is 1.4.0 for the 5D Mark IV. How many shots can you get before the camera locks up. I recommend resetting the camera back to factory default and retest with Canon brand EF lenses. NOT EF-S, EF-M, RF or RF-S lenses. Also what kind of memory cards are you using. The 5D Mark IV allows both SD and CF cards. Are both card slots being used. What brand of cards are you using and what size. Are you using a Micro SD card in an adapter. If so discontinue using them and get a Full size SD Card. Try using the camera with any memory cards in it. Does it still lock up and cause problems.

[SMPhotography20]

Thank you! i will work on getting the firmware up to date.  Honestly it just depends on the day, one session was maybe 20 minutes in, others are after 2 hours or so.  I use the extreme PRO SD cards and i have it formatted to record to both SD and CF cards.  they are both 128 GB.  i have not tried without cards but i will have too