USB storage not detected anymore
In short, it's time to throw it away &amp; get a new one.

If a USB key encounters a write error, then it will attempt to lock the device into read-only mode. If it tried to do this as power was being removed it may have failed to complete that task &amp; be left in an uncertain state.

This is, to all intents &amp; purposes, irreversible.

The solution is to discard it &amp; copy your data to a new USB key.

If for any inconceivable reason it was the only copy of that data, then your recourse would be to a specialist recovery company.

The same applies to such as SD cards, as well as USB flash drives.
Once they start to go bad, they are not worth the effort of fighting them to try squeeze a little more life out of them.
Discard &amp; replace.