Help Pls! 5D mkIII read & write RAW on my Lexar 128gb CF but Windows cannot see.

[KenshirouX]

I need urgent help!  I have a 5D mkIII and today I just did some important MLV recording on my Lexar 128gb CF card. I have been using this card for a couple of years, it's my go-to card.  The filming went very well as I would able to check all the footage on my 5D video the playback option. However, when I reached home to offload the MLV data off the card by plugging it into my Lexar USB 3.0 Reader (which I have been using ever since I got the card), the Reader cannot read the CF card and just show the blue reader light flashing on & off.  Confused, I tried connecting the reader and CF card to another machine and the same thing happened again. To check there are no problems with the reader I inserted my Komputer Bay 128gb and it worked without any problems. As a double check, I inserted the Lexar Card back into my 5D and attempted to read the files by connecting the camera to my PC via USB 2.0... Sadly, even though the camera can still read and write to the card without any problems and my PC see both the capacity and the amount of data that is used,  everything comes up as Zero bytes when I go into the folders! 

I don't know what to do and I MUST get the files off the card. 

Guys, can you help me solve this problem? Any solution/ideas at all, please help.

[Walter Schulz]

In any such situation I strongly suggest (I would use other words but this is a family-friendly area) *not* to write anything to the card!

[KenshirouX]

UPDATE (SOLVED...  Sorta) - I'm so confused. I managed to get the reader to read from the card and now successfully offloaded all the data from there. 

Now, the reason I am confused is why on earth did this work?  Check this out: I put the Komputerbay card back into the reader and the USB 2.0 cable was connected to my powered 5D MkIII (strictly convenient, not intentional). Lightroom loaded automatically due to the photos that are currently in the SD card that is inside the 5D. From looking at Lightroom, I noticed that Komputerbay was being read by Lightroom (even though lightroom cannot read MLV files). Just for the heck of it, I right clicked on the CF Reader drive in lightroom and selected "Open in Explorer". Lightroom then opened explorer and revealed all the MLV files within the Komputerbay Card as expected.  Now, in hope that somehow Lightroom can trigger something within the reader so it can access the Lexar Card or even trick explorer to look at the device differently, I replaced the Komputerbay Card with the Lexar Card. When this was done, I was, somehow, within the DCIM menu which was something I was unable to do. So from there I crossed my fingers and selected the Open in Explorer option and behold... I can access the card!! From that point I offloaded all the data from the card like no tomorrow.

Now seriously, WTH is that all about because it really makes no sense?!

For now, I think I won't be using my Lexar card for anything major anymore but I will be conducting some more test. Question is, how to truly test the card inside and out to see whether it's really on the way out or not? There must be some way to truly test it.

[Walter Schulz]

h2testw for Windows or F3 by Digirati for macOS. There is a GUI available: F3 X.

[DeafEyeJedi]

Guys, can you help me solve this problem? Any solution/ideas at all, please help.

I've had this happened to me on few occasions and pretty much narrowed down the culprit to which may have to do with using the mlv_playback.mo last in camera.

I noticed this playback module spits out .IDX files into card after each playback. Either try deleting the last .IDX file (from file manager within ML menu) or try recording a new quick MLV take after playback usage which should do the trick.