A phone or tablet problem starting right after an OS update, a new case/accessory or a restored backup should be checked against that change first. 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 the exact update version, accessory or backup date, and confirm the feature worked immediately before it. 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. Test with the new accessory removed, or check the update's known-issues note for the exact symptom. 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. Reset the one setting the update changed, or replace the incompatible accessory.
Verify and stop safely
ReversibleConfirm normal operation with the change present for one full day of typical use. Stop for heat, liquid, corrosion, bent contacts or unstable storage writes.
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