Enable developer options
Android device menus vary by manufacturer and Android version. A common workflow is to open the phone's About screen, tap the build-number entry repeatedly until developer options are enabled, then open Developer options and enable USB debugging.
Google's hardware-device setup guide explains that USB debugging must be enabled in Developer options before a USB-connected device can be used with ADB.
Open Google's hardware-device guide
Authorize the Windows PC
- Connect the device with a data-capable USB cable.
- Unlock the device screen.
- Watch for an RSA-fingerprint authorization prompt.
- Approve the computer only when you recognize the connected PC.
- Refresh SAD-B-D-M-T after approval.
Connection states
| State | Meaning | Recommended next step |
|---|---|---|
| Connected and authorized | The device can accept supported ADB actions. | Continue to backup or diagnostics. |
| Unauthorized | The cable connection exists, but the phone has not approved this PC. | Unlock the phone and approve the USB-debugging prompt. |
| Offline | ADB can see the device but cannot establish a usable session. | Reconnect the cable, restart ADB, or restart the phone if appropriate. |
| No device detected | ADB cannot currently see a connected Android device. | Check the cable, port, USB mode, drivers, and ADB selection. |
Cable and port tips
- Try a different known-good cable when the phone only charges.
- Try a different USB port on the Windows PC.
- Avoid unstable hubs while diagnosing intermittent disconnects.
- Keep the phone unlocked during the initial authorization step.