If your memory card is not showing up in the Aluminum Type-C Micro/SD Card Reader, check the LED in the SD card slot first, because that LED turns on whenever the card reader is connected correctly. The Aluminum Type-C Micro/SD Card Reader plugs straight into a USB-C port and reads an SD card and a microSD card at the same time, so both slots being empty of activity usually points at the connection rather than the cards.

How to fix card detection on the Aluminum Type-C Micro/SD Card Reader

1. Push the Aluminum Type-C Micro/SD Card Reader fully into your computer's USB-C port, then look for the LED in the SD card slot. If the LED is dark, the card reader is not connected properly.
2. Try a different USB-C port on your computer.
3. Put each card in its matching slot. A full size SD card goes in the SD slot and a microSD card goes in the microSD slot. Two cards can be used at the same time.
4. Push the card in until it seats with a slight click. A card that is only partway in will not be read.
5. Remove the card, wait a few seconds, and reinsert it.
6. On a Mac, open Finder settings, go to General, and make sure External disks is turned on so mounted cards appear on your desktop.
7. Check whether the card appears but is unformatted. Open Disk Utility on a Mac or Disk Management on Windows and look for the card in the list of drives.
8. Test the same card in another device or reader to confirm the card itself still works.
9. Try a different memory card in the Aluminum Type-C Micro/SD Card Reader to see whether the problem follows the card or stays with the reader.
10. Test the Aluminum Type-C Micro/SD Card Reader on a different computer to confirm whether the issue is the reader or the host device.