If you are looking for a specific "part3.rar" file, you are likely looking at a multi-part archive from a forum or third-party site. Be cautious with these files:
: Select Device Preferences (or System ) and then About .
: Installing incorrect or corrupted firmware can permanently "brick" your TV. Security : Third-party downloads may contain malware. Alternatives for Manual Installation
: Select System Update . If an update is available, follow the on-screen prompts to download and install it automatically.
: If you don't have all parts (Part 1, 2, and 3), the archive cannot be extracted.
: Ensure your TV is connected to a stable Wi-Fi network before starting the check. Risks of Using Unofficial Firmware