Why does Ubuntu not detect my SD card?

Run these commands from a command prompt:

sudo modprobe -r r852
sudo modprobe -r sdhci_pci
sudo modprobe r852
sudo modprobe sdhci_pci

This uses modprobe to unload and reload the device drivers (in this case kernel modules) to automatically detect the SD card into the kernel.

Source codes

• r852 driver: Ricoh 85xx xD/smartmedia card reader driver
• sdhci_pci driver: Secure Digital Host Controller Interface PCI driver