When a phone or tablet function changes with the app, network, account or location, that context is the first repair boundary. For Android USB file transfer, first use a known data cable, unlock the phone and select File transfer on a direct computer port.
What this covers
- Android USB file transfer with this exact failure state
- Diagnosis across charge-only cable versus port, host driver, USB preference and security prompt
What it does not cover
Try in this order
0 of 4 completedCapture the exact failure state
ReversibleName the failing app, network, account or location and one context that still works. Expected behavior: enumerate as a data device with the phone unlocked and USB mode selected.
Isolate the component boundary
ReversibleUse a known data cable, unlock the phone and select File transfer on a direct computer port. Swap only that context while keeping the device, line and connection settings unchanged. Boundary to separate: charge-only cable versus port, host driver, USB preference and security prompt.
Correct only the proven cause
ReversibleReplace the charge-only cable or correct the host driver/USB preference. Repair the isolated permission, app profile, carrier state or network boundary.
Verify and stop safely
ReversibleRetest the previously failing and known-working mobile contexts after restart. Stop for heat, liquid, corrosion, bent contacts or unstable storage writes.
Evidence ledger
Sources behind this answer
Exact questions