EOS R6 Mark II card slot problem "Card cannot be accessed"

[Princejvstin]

I really can't figure this one out, so maybe someone has some ideas.

About a year and change ago, I  went from a Canon 5D Mark IV to a canon R6 mark II. Things went fine at first, but then I recently noticed I am having a bunch of SD card problems. I was getting the "card cannot be accessed" error

But its' frustratingly weird how the error happens:

It only happens in slot 1.

It only happens on cards larger than 64 GB. My 64 GB cards work just fine. I have a couple of different kinds of 128 GB cards in terms of manufacturers and they all act the same way. Any card larger than 64GB doesn't work in slot 1.

So if I take a 128 GB card and put it in slot 1, it gives me the error. I put that same card in slot 2, and it seems to work fine.

If I put one of my 64GB cards into slot 1 it seems to work fine.

I've tried formatting the cards, regular and low level format, to no avail. I've tried formatting the cards on a computer. No luck there.

And it is just slot 1. Slot 2, the 128GB cards work normal. Slot 1, "card cannot be accessed". But 64 GB cards work in slot 1, no issues. (and of course Slot 2, the 64GB cards work normal)

I even toggled the write protection switch on the cards back and forth. No dice.

It's as if my R6 Mark II can't "handle" a 128GB card in Slot 1. But Slot 1 can handle 64 GB cards. And the 128 GB card works in Slot 2.

I downloaded the latest firmware in hopes that would help. No dice.

Ideas?

[melissatoms]

Just an update, a year later I am still having this same issue and have sent my camera in for Canon to repair it twice and I am STILL HAVING THE ISSUE.  Beyond frustrated at this point.  Now it happens to mine even with 64 GB cards, brand new cards, SLOT 1 just does not want to work.  Completely defeats the purpose of owning a camera with dual card slots.  I can't believe Canon can't do better on this.

[Photosamua]

Hi,

This is Samu from Finland. I have problem with my Canon R6 Mark II with card slot 2. Same issue. Occasionally gives the problem "can't acces card in slot 2". Removing it and pushing it deeper worked last time. I already bought new card, because I thought the card was the problem. It was not. Annoying, I can't trust my backup anymore.

[ToniT]

Update for my issue - I finally took the effort and time to send it to the warranty repair - they replaced the motherboard on their cost and so far the camera works fine with all combinations of any of my cards - SD, micro SD, slow or fast, regardless of the brands. It now accepts cards and is able to format them also in slot 1.
Looks like it was a hardware issue on my product.

[Tintype_18]

Not sure how this would affect the problem but I never use anything more than SanDisk 64GB. Would the high capacity of 128 GB influence in any way? Watching.

[ToniT]

In my case 64GB card from Lexar was working better. But not flawless. But I found a youtube video where Lexar cards in general were told to be problematic.https://www.youtube.com/watch?v=N2uR9M4Ua7o

After the fix they work for me. So it was the faulty camera in my case, not the cards. I tried different brands and types of cards, issues were there regardless. Canon swapped the main electronics board in the camera and this fixed the issue.

[Photosamua]

I just bought a new SD card and it works fine now. There was nothing wrong with the previous card either, though. I put the previous card in to my Canon R and the card works fine there. Weird.