ADB device not found: fix adb devices issues for phone agents

When adb devices shows nothing, Open-AutoGLM cannot talk to your phone. This guide walks through the most common failure points and how to validate each layer before you try again.

Quick diagnosis checklist

Start with these five checks before changing anything:

1. USB cable: try a known‑good data cable (many cables are charge‑only).
2. USB mode: set the device to File Transfer or MTP.
3. ADB server: restart it with adb kill-server and adb start-server.
4. Developer Options: confirm USB debugging is enabled.
5. Authorization prompt: unlock the device and accept the trust dialog.

If any of these fails, fix it first; do not jump to advanced steps.

Step-by-step troubleshooting

1) Verify the ADB server

adb kill-server
adb start-server
adb devices

If the server returns an error, reinstall the Android platform tools.

1a) Check device states

ADB can report three common states:

• device: connected and authorized.
• unauthorized: connected but waiting for trust approval.
• offline: connected but not responding properly.

If you see offline, toggle USB debugging off/on and reconnect. If it stays offline, restart the ADB server and reboot the device.

2) Confirm the device is visible to the OS

• On macOS: check System Information → USB.
• On Windows: check Device Manager for Android or MTP entries.
• On Linux: use lsusb and verify the device appears.

If the OS cannot see the device, ADB will not either. Try another cable or USB port.

3) Confirm Developer Options and USB debugging

On the device:

• Enable Developer Options.
• Toggle USB debugging off and on.
• Reconnect USB and accept the prompt again.

If you do not see the prompt, try revoking USB debugging authorizations and reconnect.

4) Handle the unauthorized state

If adb devices shows:

<serial> unauthorized

Unlock the device and accept the prompt. Then re‑run adb devices.

5) Install drivers (Windows)

Windows often needs OEM USB drivers. Install the official driver for your device brand, then reconnect and restart ADB.

6) Fix permissions (Linux)

On Linux, udev rules may block ADB access. Use the official Android platform tools guide to add udev rules, then restart ADB. TODO: add the official udev rules reference.

7) Verify platform-tools version

Old platform tools can break device discovery. Confirm you are using a recent version:

adb version

If the version is outdated, reinstall the platform tools from the official source.

Wireless ADB troubleshooting

Wireless ADB is convenient but finicky. If pairing fails:

• Confirm both devices are on the same Wi‑Fi network.
• Re‑pair using the Android pairing code.
• Avoid guest networks or VPNs that block discovery.

If wireless is unstable, switch to USB for setup and evaluation.

Multi-device scenarios

If multiple devices are connected, ADB may not know which one to use. List devices:

adb devices

Then target a serial:

adb -s <serial> devices

Use the same -s flag when running Open-AutoGLM.

Common mistakes to avoid

• Using a charge-only cable.
• Leaving the phone locked during ADB checks.
• Running ADB from a different user shell that cannot see the device.
• Using outdated platform tools.

Edge cases

• Corporate device policies: some managed devices block USB debugging entirely.
• USB hubs: passive hubs can cause unstable connections; try direct ports.
• Multiple ADB installations: remove duplicates to avoid path conflicts.

FAQ

Q: Why does my device show up, then disappear?
A: Power management or unstable USB ports can disconnect the device. Try a different port and disable aggressive power saving.

Q: Can I use emulators instead?
A: Emulators can help for early UI exploration, but physical devices are still required for realistic evaluation.

Collecting logs for support

If you need to ask for help, collect:

• Output from adb version
• Output from adb devices
• OS version and device model
• USB cable type (data vs charge-only)

This makes troubleshooting faster and more precise.

When ADB still cannot see the device

If none of the above works, do a full reset:

1. Remove the device from the system.
2. Restart the phone and your computer.
3. Install the latest platform tools.
4. Re‑enable USB debugging and re‑pair.

This is a time‑consuming step but resolves most persistent issues.

Safety note

Do not use ADB on a personal or production device for early experiments. A single wrong command can alter device settings or data. Keep tests isolated.

Next steps

• Continue with Open-AutoGLM installation.
• Review model service endpoints if local GPU setup is blocked.