A feature that drops and returns on a phone or tablet is usually a background battery-optimization or connection-management setting killing it, not failing hardware. 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
ReversibleNote how long the device was idle or locked before the drop, and whether it correlates with low signal or a Wi-Fi handoff. 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. Disable battery optimization for the one app and test with the device kept awake on a single network. 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. Exempt the app from aggressive battery management, or turn off adaptive Wi-Fi/cellular switching for the test.
Verify and stop safely
ReversibleRun the same use pattern that triggered the drop for at least 30 minutes without it recurring. Stop for heat, liquid, corrosion, bent contacts or unstable storage writes.
Evidence ledger
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