My Ender 3 is showing SD Init Fail when the sd card is inserted. I tried rebooting, reformating the card etc. At first, I thought the card is damaged, so I bought a new card. Still the same. I can use the card with the computer without any problem.
Also, I tried to print from Cura 5.3.0. But the printer is not detected.
What could be the reason? Since the SD card is not detected, I can't even flash the firmware
A possible fix that worked for me is to convert your SD card from GPT to MBR.
Modern systems will usually initialize them in GPT, which seems to be incompatible with Creality boards.
At least with my 4.2.7 board, this was the solution. And obviously, it has to be formatted in FAT32.
Instructions on how to do it are available at Convert a GPT disk into an MBR disk.
I think it's worth a try.
I had a similar issue with an old Ender-2 from 2019.
In my case, this happened because I was using fancy 32 GB, Class 10 or UHS 2 SD cards. It stopped happening when I started using a cheap 512 MB, no class visible card.
Try at least using a card with lower capacity, like maximum 2 GB and see what happens. You can also try using short names with no spaces for the G-code files, and leaving more free space on the SD card.
If the problem is still happening, then it might be a SW issue. Obviously, you can't flash via SD if the card is not detected, but this is likely solvable by upgrading the Marlin version (the factory version may be really old!) or just flashing a clean build. One way to flash the Firmware without the card could be by using an ISP or an ISP-USB cable.
Copying all the files to my computer and then reformatting the microSD as FAT32 worked for my 3D printer.
