Unbricking yet another bricked BU40N

[Icer_CRO]

Dear all,

I'm pretty new to the BD-Rabbithole and seem to have bricked my new Verbatim 43888 drive. Is there any way to unbrick this device?

I did the following:
1) before doing anything I read and dumped the original FW using the SDFTool Flasher. The flash seemed somewhat small in size, but I decided to move on (can't seem to post screenshots yet, see directory listing at the end)
The original FW was 1.05 encrypted.

2) I reflashed to 1.03 I got from a link in this forum. This worked without a hitch, and libre-drive was active and functional.

3) I was having problem with a 1st disk I wanted to play - this was the 1984 Dune in BlueRay I bought off Amazon for this purpose. The backup and the reading process stopped at the same time, at about 1:02:20 into the film. No visible damage on the disk. For playback I used VLC - I can not say if there was some sort of protection on the BD, but there probably is. I could not jump forward during playback after this point. "Assumed" disk was faulty and asked for a replacement.

4) Tried to reflash the BD again with the "original" LG flasher with 1.05 FW. https://www.lg.com/us/support/product/lg-BU40N.AVAA10B
The flashing process started and got to 48% then crashed. After this, my device is essentially bricked and only the "boot" tag is shown in both MakeMKV and in Windows. The drive is totally unresponsive, won't open, and is not registered as a "1959" flashable drive.
I tried forcing a flash with the makemkvcon64.exe but this failed and reported a standard bin error for this case.

My question:
Is dosflash worth trying in my case?
Since the drive is a USB drive, I'm not sure how the backward compatibility can be solved (the examples on the internet warn to use IDE modes for drives), in an instance of Windows 7 PE I started, the usb drive was not visible. Can you recommend any specific drivers or software that is required to do this?

The firmware dump in my case is as following:
Volume in drive C is Boot
Volume Serial Number is 7C97-0E1E

Directory of C:\Users\icer_\Downloads\Firmware_Dumps\dump_user_HL-DT-ST_BD-RE_BU40N

23.12.2025 16:16 <DIR> .
23.12.2025 16:16 <DIR> ..
23.12.2025 16:16 0 dir.txt
18.12.2025 20:51 28 fd_fwdate.bin
18.12.2025 20:51 28 fd_sn.bin
18.12.2025 20:51 96 inq.bin
18.12.2025 20:51 32 rom_003000.bin
18.12.2025 20:51 256 rom_1EC000.bin
18.12.2025 20:51 65.536 rom_1F0000.bin
7 File(s) 65.976 bytes
2 Dir(s) 147.692.539.904 bytes free

The dump made is a few KB in size at most. Is this a failed FW dump or is this data actually usable for reviving a drive via dosflash? I would at least reflash to the 1.03 that worked before.

Thank you in advance!
Nick

[Coopervid]

1) This only saves the calibration data and NOT the whole firmware

2) Try again with SDFTool or the LG original flasher. If both fail try the modified ASUS flasher from here in the "Unlocked flashers" section:

viewtopic.php?f=16&t=19634

If successful don't panick next time. Most likely your drive didn't get enough power. Use an USB-C port or connect both USB-A connectors.