Why your USB device isn’t showing up on your MacBook and how you can fix it

macOS may fail to recognise a USB accessory because of a permission setting, insufficient power, a faulty connection or software compatibility issues. The article outlines checks MacBook users can try before seeking technical support.

First, unplug and reconnect the accessory to bring back a connection permission prompt, or review accessory access under Privacy & Security in System Settings. Check whether the device appears in System Information, try another USB port or connect directly instead of through a hub, and make sure the hub has power. Updating macOS and any manufacturer software may help; external drives and cards also need a macOS-compatible format such as APFS, FAT or ExFAT.