www.makemkv.com

tobyreid00 wrote: ↑

Thu Jan 15, 2026 1:44 am

Hello all & thank you in advance for the help. I have a Product: BD-RE BU40N Revision: 1.05 which came in a Verbatim 43888. I have read through all of the documentation (2026 UHD thread & SDFlasher thread) AI assisted searching also. According to my AI assisted searches, it will work to flash this drive, but I have not found a post from a person who actually flashed the BU40N 1.03MK firmware to this drive w/this 1.05 firmware... I found 1.04 firmware examples, but not 1.05. If anyone has, please let me know. Or, if you know this won't work, please let me know that too.

Here is the full drive info from makemkv:

Drive Information
OS device name: D:
Manufacturer: HL-DT-ST
Product: BD-RE BU40N
Revision: 1.05
Serial number:
Firmware date: 2124-04-23 13:47
Bus encryption flags: 17
Highest AACS version: 31

LibreDrive Information
Status: Possible, not yet enabled
Drive platform: MT1959

SalsaForte wrote: ↑

Wed Jan 21, 2026 3:56 am

I'm in the same situation. So, basically it is 100% safe and it's working to downgrade the drive from 1.05 to 1.04 (MK).
The last answer doesn't explicitly mention those thousands of Verbatim drive were downgraded.

I better be safe than sorry.

MartyMcNuts wrote: ↑

Wed Jan 21, 2026 5:27 am

Yes, of course they were downgraded. There is no such thing as BU40N 1.05-MK firmware!

BU40N 1.04-MK is not the recommended firmware. I flash them to BU40N 1.03-MK to remove the firmware encryption then to BU40N 1.00 for wider UHD ripping software compatibility. If you only use MakeMKV or Xreveal for ripping UHD discs you can leave it on BU40N 1.03-MK.

SalsaForte wrote: ↑

Wed Jan 21, 2026 12:34 pm

MartyMcNuts wrote: ↑

Wed Jan 21, 2026 5:27 am

Yes, of course they were downgraded. There is no such thing as BU40N 1.05-MK firmware!

BU40N 1.04-MK is not the recommended firmware. I flash them to BU40N 1.03-MK to remove the firmware encryption then to BU40N 1.00 for wider UHD ripping software compatibility. If you only use MakeMKV or Xreveal for ripping UHD discs you can leave it on BU40N 1.03-MK.

Then, I'll need to find the 1.03-MK firmware. The link available on this very forum led me to a .zip file containing 1.04, not 1.03. I may have misunderstood or misread something.
And can you point me to information on why 1.04-MK isn't recommended? Curious to understand more about this.

Thanks Marty! Your feedback is appreciated.

MartyMcNuts wrote: ↑

Wed Jan 21, 2026 10:20 pm

Newer does not mean better. After extensive testing, us drive sellers determined that v1.03-MK was the better of the two firmware version for reading UHD discs. Personally, I downgrade all BU40N's to v1.00 for wider UHD ripping software compatibility as the MK firmware only works with MakeMKV and Xreveal for UHD discs.

If you are looking in the MK firmware pack, 1.03-MK is in the "old" folder. If you grab my "all you need" firmware pack from the same post where you get the SDFtool Flasher, you will also find it.