Today I had a Nintendo Switch come through that was not recognising an SD card inserted into the card slot. Initially I thought it may have been a faulty SD card slot and or bent/missing pins in the slot. After opening the console to replace the slot,replacing the slot and still having the same issue. I dove in deeper and found that the connector on the motherboard had a missing pin.

I then went ahead and replaced the connector on the motherboard and this fixed the issue. The card slot was also faulty and needed replacing.

A successful repair and the Switch is now recognising an SD card in the system.