Corrupt SD Slot? Canon 5D MK3 won't turn on.

[lblum]

I've had a strange issue happen several times in the past two months. My Canon 5D MK3 isn't even 2 years old at this point, and I'm the only owner.

Suddenly one morning before a wedding - my 5D MKIII would not turn on. After removing the batteries, including the clock battery, and waiting a while, I was able to reset the camera. After various tests, I've narrowed this issue down to introducing the SD card.

It doesn't matter if I have zero cards in my camera or a CF card already inserted - when I insert any SD card I have (I only use Sandisk Pro Extreme cards), my 5D will shut off and won't turn back on. I can insert the same SD card into my Canon 6D and I'll have no issues. Sometimes rather than shutting off, it will allow me to access the Quick Screen and menus, but will not fire.

Has anyone ever experienced something like this?

[Waddizzle]

" I can insert the same SD card into my Canon 6D and I'll have no issues. "

Actually, putting it into a 6D could be an issue.  What size is the card?  Is it a full size card?  Try a blank card, if you can.

[lblum]

Hi there! Thanks for your response. I've tried a variety of 32GB and 64GB cards, sometimes they were empty, sometimes they had a few images on them.

My camera will stop working as soon as I insert the SD card.

[Waddizzle]

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@lblum wrote:

Hi there! Thanks for your response. I've tried a variety of 32GB and 64GB cards, sometimes they were empty, sometimes they had a few images on them.

My camera will stop working as soon as I insert the SD card.

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Uh, I assume that the camera is turned off when you insert the SD card.  Right?

[lblum]

Yes, always. Camera is always off when I access the memory card slot.

[lblum]

Once the camera won't turn on or won't fire, at that point I will then remove all batteries, including the clock battery, and let it sit for 30 minutes. After setting the camera back up, it will then work roughly half the time. The other half, it will do exactly as before - it won't fire or simply won't power up.

[Waddizzle]

Only use full size SD cards.  Inserting a memory card that has been used by another camera can cause the next camera you put it in to seemingly malfunction. 

What does "work roughly half the time" mean?  If there is no card in it, how is it working?

[EDIT]  Make sure that the card slot door and battery compartment door are securely and properly closed.

[lblum]

By half the time, I meant that after a full camera reboot, it will sometimes work correctly with the SD card or both SD and CF cards, and sometimes it will still not turn on. If it doesn't turn back on I simply go through the reset process again.

In these instances, the card was not inserted into the 6D prior - I just picked up the 6D a few weeks ago and this has happened since earlier this year.

[Waddizzle]

Okay.  It sounds like you should call Canon U.S. support at 1-800-OK-CANON. 

Make sure your doors are closed, and that you are using full size cards.  No mini cards with adapters.

[lblum]

Thanks again, I will give it a go.

And yes, doors are definitely closed. I've tried with both empty cards, empty formatted cards, cards that were partially full. Never mini cards + adapters.

I really appreciate your time and thoughts - thank you very much!