With firmware 1.00, the BU40N becomes "UHD Friendly." It allows you to insert a legally purchased 4K movie and back it up to your local media server (like Plex or Jellyfin) as an uncompressed MKV file. The Threat of Newer Firmware (1.01, 1.02, 1.03+)
Click the "Start" or "Write" button. Do not turn off your computer or unplug the drive during this process.
| Firmware Version | Type | Key Features & Use Case | | :--- | :--- | :--- | | | DE | "D.E." (likely Drive Enabled ) 🔹 Max Software Compatibility (DVDFab, MakeMKV, Leawo). 🔹 Official but has LibreDrive support enabled. | | 1.03-MK or 1.04-MK | MK | Patched by MakeMKV community. 🔹 Often the first step in the flashing process. 🔹 Works with MakeMKV but may have limited compatibility with other ripping software. | | Stock Firmware (1.01, 1.02, etc.) | Official (Unpatched) | Untouched drive firmware. 🔹 May NOT be 4K/UHD compatible. 🔹 Does NOT support LibreDrive. | | Other Variants (-N, -FR, etc.) | OEM | Branded/specific firmware for different companies. 🔹 Must be cross-flashed to DE or MK to work. |
The BU40N 1.00 firmware is unique because it lacks these aggressive, updated AACS 2.0 execution blocks. While it was not intentionally designed to bypass security, its code allows software tools like MakeMKV to read the volume keys directly from the disc. By flashing your drive back to firmware version 1.00, you turn an encrypted, locked-down drive into a "UHD-friendly" powerhouse capable of reading 4K discs for archiving purposes. Benefits of Downgrading to BU40N 1.00
If your BU40N is in an external enclosure, plug it directly into a motherboard USB port. Do not use an unpowered USB hub, as unstable voltage can cause flash failures.
To activate LibreDrive on your BU40N, you need to flash a .
Download the clean, patched firmware pack (often found on the official MakeMKV forums under the "Ultimate UHD Drives Flashing Guide"). Locate the specific file labeled for the .
The BU40N holds a specific place in the enthusiast community (notably on forums like MyCE or VideoHelp) because of its potential for customization. The 1.00 firmware is often the target for modification.
By saving your physical discs from repetitive scratches and wear-and-tear, you preserve your expensive media collection indefinitely.
Despite being the "original" firmware, version 1.00 remains highly relevant today. The enthusiast community continues to actively discuss and use it as their preferred firmware over more recent versions. It's widely regarded as a stable, compatible foundation for any UHD-related tasks on the BU40N platform.
The remains the preferred operating software for users who require a portable 4K UHD ripping solution. It offers the best balance of speed, compatibility, and "friendly" functionality, making it worthwhile to keep or downgrade to if you are experiencing issues with newer firmware versions.
The LG BU40N remains one of the best optical drives on the market for media enthusiasts, but its true potential is locked behind factory restrictions. Finding and flashing the acts as a master key, transforming a standard burner into a restriction-free archiving machine. By taking the time to carefully downgrade your firmware, you can build a future-proof, digital library of your favorite 4K cinema.
. It facilitates cross-flashing on drives like the LG BP50NB40 and acts as a "Gold Standard" for achieving stable, high-speed UHD read performance . For technical details and flashing guides, visit MakeMKV Forum
The Ultimate Guide to BU40N 1.00 Firmware: Unlocking 4K UHD Blu-ray Ripping
The firmware update also includes several improvements:
: It fully enables LibreDrive, allowing the drive to read data directly from the disc without the hardware-level interference common in newer versions.
