You may check from below several aspects:
1. Confirm the form of the SD card meet the requirement;
2. Make sure your Split has been turned off (the battery of the quad is removed) before you connect it to the computer by USB, and then turn it on. (If it failed to be turned on, please long press the power button.)
3. Replug the SD card and wipe the metal contact to make sure there is no dust on it.
4. Try other SD cards and other USB cables.
5. Check if there is any obvious broken part on the USB port or the connector of the cable. You may try to push the contacts inside the USB port on the PCB a little bit up or down by tweezers to make the USB cable inserted in more steadily.
6. Sometimes, insufficient power supply via USB port from the computer may lead to this situation as well. (Split's working current is about 650mA). Please try USB ports on the back of the host or other computers.
If the problem persists, please send us
- HD pictures of the USB port part on the Split's PCB
- a video showing your problem