I experienced the dreaded Safety Override / SD card fail screen again and was able to recover by having a back up of the SD card and replacing the defective 4Ggb card with a quality one of recent manufacture. (Sandisk) I lost four jumps, but saved the device. I have the info from the jumps because I have been jumping with more than one device since the first time I had a Dekunu fail on me. (this makes four times) I was concerned that the device might not recognize a larger card, but so far it hasn’t complained about the new card being 64Gb. So, a word to the wise if you wish to keep using your Dekunu for a while longer - keep your card backed up so you can replace it in the absence of actual Dekunu parts support in the future. (Though I sincerely hope that they do get back to operation and support. It’s a nice device when it works.)
How does one replace the card?
The device has to be opened up. This is trivial. A small, thin, rigid tool helps to open the two halves. I used a razor blade to slip between the halves and assist separating them. Once open, take note of how the battery and wiring resides, so as to make sure that reassembly goes correctly and smoothly. The SD card is located near the corner of the circuit board, and can be pulled from its mounting socket. You may need a tweezers to obtain enough purchase upon it. Be careful. All in all, it’s a very straight forward effort. I used the Dekunu yesterday. Good luck!