Symptoms
- Drive doesn't appear when plugged into any computer
- Drive light flickers but nothing shows in file explorer
- Drive is recognized but shows 0 bytes or asks to be formatted
Likely causes
- CommonLoose or damaged USB connectorBent pins or a worn connector can prevent a solid connection.
- CommonCorrupted file system on the driveImproper ejection or power loss during use can corrupt the drive's file table.
- PossibleFailing flash memory controllerCheap or aging drives can develop controller faults that make them undetectable.
- PossibleUSB port issue on the computerA faulty port can make a working drive seem dead.
- Less commonPhysical damage to the driveDrops, bends, or liquid exposure can permanently damage internal components.
What to do
- Try the drive in a different USB port and a different computer.
- Look for the drive listed in Disk Management (Windows) or Disk Utility (Mac) even if it doesn't show a drive letter.
- Try a different known-good USB cable if the drive uses one.
- If it asks to be formatted, that means it's detected but the file system is damaged; recover data first if possible before formatting.
- Avoid repeatedly plugging and unplugging while it's being detected, which can worsen a marginal connection.
- Use manufacturer diagnostic tools if available for your drive brand.
- Consider a data recovery service if the drive holds important unrecoverable files.
When to call a pro
If important data is on a drive that isn't detected anywhere, stop using it and send it to a professional data recovery service rather than risking further damage.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.