What (Windows, macOS, or Linux) are you using to perform the flash? Is your drive internal or inside an external USB enclosure ?
The LG is considered "hot" or highly desirable because it is the original unpatched firmware that allows for maximum software compatibility, particularly with 4K UHD ripping tools. Why Firmware 1.00 is a "Hot" Feature
Slim drives like the BU40N are notorious for dropping into low-power sleep states. If the drive goes to sleep halfway through a 4K rip, you may need to disable USB selective suspend settings in your Windows Power Management panel. Conclusion: Is It Worth It?
The BU40N is designed to work in either orientation, but providing space around it can help heat escape.
This is a common fear. If you tried to flash firmware and the drive stopped responding (dead), do not panic. bu40n 100 firmware hot
An LG BU40N drive installed internally in a laptop, or housed inside a high-quality external USB 3.0 enclosure (like an OWC Mercury Pro or Vantec NexStar). The Software: Download the latest version of MakeMKV .
While not officially documented as a "hot" running drive in terms of temperature, the constant re-reading and mechanical stress from failing to read discs can lead to the drive feeling exceptionally hot and potentially failing prematurely. Symptoms of a "Hot" (Unstable) BU40N 1.00 Drive Go to product viewer dialog for this item.
| If you... | Then... | | :--- | :--- | | Use your BU40N daily to rip discs | Your drive will thank you. | | Use your drive once a month for 10 minutes | You may survive on 1.00, but still, why risk it? | | Are a collector preserving a rare 1.00 drive | Buy a second BU40N. Keep one on 1.00 (in a box), use the other on 1.03-MK. |
The BU40N is an ultra-slim laptop-style drive. Because it lacks a dedicated internal fan and has a small physical footprint, it generates significant heat during the 45–90 minute process of ripping a 4K disc. What (Windows, macOS, or Linux) are you using
In the world of Blu-ray drives, firmware acts as the operating system for the hardware. It controls how the laser reads discs, implements copyright protections, and manages read speeds. The BU40N usually ships with a variety of firmware revisions (1.00, 1.03, 1.04, A103, BW42, BW43, U100, etc.). However, version 1.00 is distinct because it is often the most "friendly" toward unlocking LibreDrive features.
This is why the search query exists: people are desperate to downgrade to 1.00 or find a drive that still has it.
Look for DE_LG_BU40N_1.00.bin within the "All You Need Firmware Pack" widely shared on the MakeMKV Forums .
Unlike newer "MK" (MakeMKV-specific) patched firmwares like 1.03-MK or 1.04-MK, the 1.00 "DE" (Downgrade Enabled) version is widely compatible with a broader range of software, including DVDFab and Xreveal . Why Firmware 1
: It enables the drive to read and decrypt 4K UHD Blu-ray discs, a feature often disabled in newer factory firmware to comply with stricter DRM.
Restart your computer to let the operating system register the newly flashed drive hardware profiles. Common Troubleshooting Pitfalls
Firmware versions later than 1.00 (like 1.01, 1.02, or the dreaded 1.03) often include patches that block "backdoor" access to the disc’s data. Version 1.00 allows software like to bypass these restrictions, letting you create a 1:1 backup of your 4K movies for a home media server (like Plex or Jellyfin). 2. No "Sleep" Bugs
LibreDrive is a feature of MakeMKV that bypasses the AACS encryption. On the BU40N, the most stable platform for enabling LibreDrive is firmware 1.00. While version 1.03 MK is often recommended for a first flash to "break the encryption," the community consensus is that version 1.00 is the absolute best for the BU40N if you want maximum software compatibility across MakeMKV, Linux, and DVDfab.