**Verizon (One Talk) versions of Yealink phones like the T35W use proprietary firmware that locks them to Verizon's provisioning servers and often disables the web interface.** To use them with an open-source PBX like FreePBX or FusionPBX, you typically need to flash standard/generic Yealink firmware. This process has worked for many T3/T4 series models (including T35W/T46G/etc.), but success depends on the exact current firmware version.
**Warning:** Firmware flashing carries a risk of bricking the phone if done incorrectly. Work on a local isolated network if possible, back up settings if accessible, and proceed carefully. You may need a Yealink power adapter (not just PoE) for easier offline steps.
### Primary Method: Offline Factory Reset + Enable Web + Flash Generic Firmware
This is the most commonly reported successful approach for Verizon One Talk Yealink phones.
1. **Disconnect from the internet/network** (unplug Ethernet if using a power adapter; for PoE, isolate the phone or use firewall rules to block outbound internet while keeping local access).
2. **Factory reset the phone**:
- Power on the phone.
- Hold the **OK** button (center of navigation) for 7–10 seconds until "Factory Reset?" appears.
- Confirm with **OK**.
- The phone will reboot (still on Verizon firmware initially).
3. **Enable the web interface (offline)**:
- After reboot, go to **Advanced** (default password is usually "admin" — enter it using old cellphone-style keypad input: 2-3-4-666-44 for "admin" if needed).
- Navigate to **Network** > **Web Server** (or similar).
- Enable **HTTP** (port 80), save, and reboot (cancel any immediate reboot prompt if offered).
4. **Set static IP with broken gateway (to keep it offline)**:
- In **Advanced** > **Network** > **WAN Port** > **IPv4**.
- Change from DHCP to **Static**.
- Enter a valid local IP, subnet (255.255.255.0), and set **Default Gateway** to something invalid like **7.7.7.7** (this prevents internet access).
- Save and reboot.
5. **Connect to network and access web UI**:
- Plug in Ethernet (now on local network).
- Find the phone's IP (press OK button or check your DHCP server).
- Log in via browser: Default credentials are usually **admin** / **admin** (or the keypad "admin").
6. **Upload generic Yealink firmware**:
- Download the latest (or compatible) firmware for T35W from the official Yealink support site (search by model).
- Go to **Settings** > **Upgrade** > Browse and select the .rom file.
- Upload/upgrade. The phone should reboot with standard Yealink branding and UI.
7. **Post-upgrade**:
- Factory reset again if needed.
- The phone should now allow normal provisioning (it may reach out to Yealink's RPS/YMCS; you can disable this).
- Configure manually via web UI or set up auto-provisioning with your FreePBX/FusionPBX (point to your provisioning URL, usually something like `
http://your-pbx-ip/app/provision`).
**Note:** On some models (e.g., T46S), the absolute latest firmware may fail—try a slightly older compatible version like 66.85.0.5 first, then upgrade further.
### Alternative: t*f*t*p Recovery Mode (for stubborn/bricked cases)
If the above fails or web access isn't possible:
- Use t*f*t*p recovery (hold speakerphone button while powering on, etc.).
- Yealink provides recovery files via support ticket (prove ownership).
- Rename the .rom file appropriately and serve via t*f*t*p server (e.g., PumpKIN).
- This is more advanced—search for "Yealink t*f*t*p recovery T35W" or contact Yealink support for files.
### After Flashing: Provision with FreePBX or FusionPBX
- Factory reset the phone.
- Use the web UI (**Settings > Auto Provision**) and enter your PBX provisioning server URL.
- Or let the PBX push configs (FusionPBX has excellent Yealink support; FreePBX via Endpoint Manager or manual templates).
- Ensure the phone is on recent generic firmware for best compatibility.
### Additional Tips & Resources
- Verizon phones may be tied to their RPS account—contact Yealink support (ticket.yealink.com) for MAC removal if it keeps re-provisioning to Verizon.
- Test on a local network first.
- Communities like Reddit r/VOIP, FreePBX forums, and FusionPBX docs have model-specific experiences.
- Official Yealink firmware: support.yealink.com (search T35W).
If you run into a specific error or firmware version on your phone, provide details for more targeted help. Many users successfully repurpose these phones this way.