I don't think you're incompetent, but I also am not a mind reader to know WHAT TESTS were performed. Basic Troubleshooting 101 is to work backwards in order to eliminate the obvious points of failure. Failures are often repeatable, too.
1. You never articulated that you had physical possession of the cards. You simply stated they were mailed back to Viofo.
2. I don't know you in person. I realize others on here have met you before, and you run a dashcam installation business, but my knowledge of your business model is limited. You now state "Full Service", which offers clarity.
Yes we tested in multiple computers. My business partner tested on his computers and when I recieved the sd cards(Because everything gets sent to me before we ship back to China) i also tested them on my Macbook air and my Macbook Studio.
1. OK so now you've answered the first question. These cards were tested in multiple computers and failed to be recognized by the card reader.
When an sd card is not being read I take the following steps
1. I use an sd card adaptor insert into main SD card slot on macbook studio. If for some reason it is not read.
2. I grab another micro sd card adaptor and retry again
3. If that does not work I use my USB C adaptor and insert micro sd card directly into the adaptor, plug it into my mac studio or macbook air and try again.
When it will not even appear on the screen or says drive is not accessible (I did not think to document it at the time)
On a Mac computer I will go directly into Disk Utility to see if I can do a format of the sd card. Or if it will even see it.
I have brought way more SD cards to life. But these ones in this particular situation were very weird. I have seen this type of SD card before but usually on an sd card that someone has been using in their dash camera for like 5 years. Not a few months.
2. So now you've offered PRECISE troubleshooting steps,
with a Caveat.
A. You stated the Viofo Cards are from different batches. This eliminates a bad batch, but does not specifically eliminate a manufacturing defect in the NAND / Controller.
B. Without testing other brand cards (Aside from Vueroid), you cannot eliminate the problem being a Viofo Only issue versus a universal one. If you tested a few other manufacturers, and repeated the card failure issue with other brands, then you've identified the issue is in fact a problem with Thinkware Firmware.
C. After confirming "
B", you then work backwards to identify the exact firmware where cards worked and the first firmware where cards don't. Thinkware can then analyze their code.
My intentions are always to help troubleshoot. I've contacted MANY MANY companies about issues with their products, identifying bugs, etc. Recently, I re-contacted a company's executive team again (after finding bugs in their firmware a few years ago), and they SERIOUSLY remembered me. That says something about my abilities.
I'm not being rude or making any implications about your testing skills, but I can only help troubleshoot based upon the information I'm given. The steps above would be how I would go about troubleshooting myself.
NOW TO BETTER UNDERSTAND WHY THIS POST HAPPENED
-Tuesday June 24th shipped package to Viofo with defective units and defective SD cards we do this maybe 2 times a year.
-Saturday June 27th we confirmed that Thinkware U3000 Pro (original manufacturing run installed in November 2025) Customer did update a few days prior and SD card was confirmed to be bricked.
-Saturday morning I made the post on DCT confirming my suspicions that this must somehow be related to the update.
When I originally made the post i assumed that there would be people posting saying something along the lines of
"I noticed in February my Samsung Pro Endurance stopped working"
"I noticed my Sandisk High Endurance stopped working in March after the update"
But surprisingly complete crickets. Which means possibly this is only a Viofo SD card issue with new update in U3000 Pro.
So why the compatibility challenge all of a sudden? Really confuses me because I find the VIofo SD card to test as better quality than the Thinkware.
Understand your intentions for posting. It's the reason why I offered further advice to expand upon your methodology, in order to determine whether the problem is relegated to "Viofo Only" or affected other manufacturers.