topic Re: Delkin CFExpress 2TB Locking EOS R3 in Camera Accessories

Delkin CFExpress 2TB Locking EOS R3

H2OCamVid — Tue, 06 Jan 2026 18:50:48 GMT

Long time CPS member. First time post on the Forum.

Circa late 2023/early 2024, I purchased a Delkin CFExpress (Power) 2TB card. In mid-2025, I noticed there was a camera delay when inserting the Delkin CFExpress (Power) 2TB card. Normally, after inserting a card, the card access / writing indicator light would quickly flicker and then turn off. The issue I noticed was that the light would remain on a bit longer (2-3 seconds).

Fast forward to September 2025, and the camera light would turn on and remain on after I inserted the card. When this happened, the camera would not respond to any input - it would lock up. The screen remained blank. Removing and replacing the battery and card would sometimes fix this. On a few occasions, I found that if I erased the card on my computer (Mac), this would also eliminate the problem. After a few more times, all of these fixes stopped working.

In November 2025 of this year, I reached out to Delkin. They offered to replace the card for free since they agreed there was a problem with the card. I asked them to not ship it until December. I received the card and started using it the week prior to Christmas 2025. After 3 days, I noticed there was a delay in the Card access/writing indicator light (remained on 2-3 seconds longer than usual) after I inserted the card.

On 31 December 2025, the problem returned.

When I insert the card, with the camera off, the light turns red and remains on for approximately 10 seconds. After the light turns off, I turn the camera on, the light turns on again and remains red for 10 seconds. Once the light goes off I can hit the Menu button and proceed to Format the Card. When the screen (to format) appears, there is no indication of how much data is on the card. There is a dash (-) and it states, "Low Level Format" with the option to Cancel or OK. When I click OK a new screen appears stating, "Cannot Format. Change Card". When I try again (from power off to on) a new screen appears stating, "Card 1 cannot be accessed. Reinsert/change the card or format card with camera."

Since I have another camera (Canon R5), I decided to use the R5 camera to see what would happen. The red light came on and locked the camera. After approximately 5-6 seconds, the red light turned off and I was able to format the card. I removed the card from the R5 and placed it back into the R3. The R3 camera immediately responded without hesitation and I was also able to format the card.

On 02 January 2026, when I inserted the card into the R3 or R5, the light remained red and would not turn off - both cameras locked up. I waited over 1 minute but the light remained on. This is same problem I had with the previous Delkin CFExpress (Power) 2TB card. I removed the card from the camera, placed it into my computer (where I could still see and access all of the files on the card), erased it, formatted it, and removed it from the card reader. From here the are two options:

Option 01: I place it back in the R3. The light remains on for 10 seconds and I get the error it cannot read/access the card. Camera is locked up.

Option 02: I place it in the R5 (2nd camera). The light remains on for approximately 10 seconds and then I can access the Menu and format the card. I then place it back in the R3 and the R3 can format the card.

I'm wondering if anyone else has experienced this or can provide additional information or recommendations.

Canon Firmware: 1.9.0 (R3) & 2.2.0 (R5) *Please note, I experienced the same problem with the 2TB card with the previous camera firmware versions.

Card Reader: Delkin Devices DDREADER-56

I have and use (for several years) two Delkin Black 325GB cards. I have never experienced any problems with these cards.

Re: Delkin CFExpress 2TB Locking EOS R3

shadowsports — Tue, 06 Jan 2026 19:42:18 GMT

Greetings,

One card, two cameras, same behavior... It's the card. Since you had it replaced, it's likely the card's firmware. Do you happen to know if the replacement card came with the same firmware as the original? Since you have a Delkin reader, are you able to check or upgrade the firmware on that 2TB card?

Re: Delkin CFExpress 2TB Locking EOS R3

H2OCamVid — Wed, 07 Jan 2026 06:54:53 GMT

Thanks for the recommendation. I’ll see if that’s possible. Per a quick internet search:

Delkin does not list a firmware update utility for CFexpress cards on its support/download pages. Their support tools focus on card readers and utilities for reader mode switching, not updating the card controller firmware itself.

Re: Delkin CFExpress 2TB Locking EOS R3

shadowsports — Wed, 07 Jan 2026 07:47:57 GMT

Just starting to poke around.

CardDoc Memory Card Health Check Software - Delkin Devices https://share.google/6tS6HFYDRLnvKxUbG

Why does this show "new" for the R3? 🤔

CFexpress™ Cards Explained - Delkin Devices

https://share.google/yZQbEIj2EH6brCp01

By chance have you reached out to Canon support to report/discuss the issue?

Re: Delkin CFExpress 2TB Locking EOS R3

H2OCamVid — Thu, 15 Jan 2026 21:29:28 GMT

Update: Delkin sent a V4.0 CFExpress (Power) 2TB. I am going to test it over the next few days and provide feedback. I also had a conversation with Canon Professional Services. They took the information and agreed to conduct some research to see if anyone else has run into the same issue.

Again - thank you Delkin for the fast responses and active support.

ShadowSports. I will take a look at the link. I'd love to see feedback from users of the program.

Re: Delkin CFExpress 2TB Locking EOS R3

shadowsports — Fri, 16 Jan 2026 03:05:48 GMT

Glad to hear Delkin is stepping up to the plate. Please keep this thread updated as it may be helpful for others. 😉