Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

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steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

I apologize if this isn't in the right spot. I've lurked all over these, but never posted until now.

I recently purchased an LG BP50NB40 (SVC NB52) and cross-flashed it using SDFtool Flasher with the BU40N DE firmware. I ensured the bootloader was checked this last time and verified in LibreDrive that the firmware is patched (microcode access re-enabled) with BD raw data and metadata read enabled.

Drive info shows Firmware version 1.03, MT1959 platform, and Highest AACS version: 66.

All-region DVD support and unrestricted read speed are active.

I’m able to read and rip standard Blu-ray discs just fine with MakeMKV, but UHD discs are not being detected. I suspect this may be due to my firmware version or microcode limitations. Anyone have any ideas? Let me know if you have more questions. Regarding the below, when a UHD is inserted, it just says no disk found. For what it's worth I tried with Atomic Blonde, Doctor Sleep, and Jurassic World.

Drive Information
OS device name: \Device\CdRom0
Current profile: BD-ROM
Manufacturer: HL-DT-ST
Product: BD-RE BP50NB40
Revision: 1.03
Serial number:
Firmware date: 2120-05-07 09:17
Bus encryption flags: 17
Highest AACS version: 70

LibreDrive Information
Status: Enabled
Drive platform: MT1959
Firmware type: Patched (microcode access re-enabled)
Firmware version: 1.03
DVD all regions: Yes
BD raw data read: Yes
BD raw metadata read: Yes
Unrestricted read speed: Yes
MartyMcNuts
Posts: 3939
Joined: Wed Nov 22, 2017 11:45 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by MartyMcNuts »

steeledrum wrote:
Mon Sep 01, 2025 7:34 pm
I apologize if this isn't in the right spot. I've lurked all over these, but never posted until now.

I recently purchased an LG BP50NB40 (SVC NB52) and cross-flashed it using SDFtool Flasher with the BU40N DE firmware. I ensured the bootloader was checked this last time and verified in LibreDrive that the firmware is patched (microcode access re-enabled) with BD raw data and metadata read enabled.

Drive info shows Firmware version 1.03, MT1959 platform, and Highest AACS version: 66.

All-region DVD support and unrestricted read speed are active.

I’m able to read and rip standard Blu-ray discs just fine with MakeMKV, but UHD discs are not being detected. I suspect this may be due to my firmware version or microcode limitations. Anyone have any ideas? Let me know if you have more questions. Regarding the below, when a UHD is inserted, it just says no disk found. For what it's worth I tried with Atomic Blonde, Doctor Sleep, and Jurassic World.

Drive Information
OS device name: \Device\CdRom0
Current profile: BD-ROM
Manufacturer: HL-DT-ST
Product: BD-RE BP50NB40
Revision: 1.03
Serial number:
Firmware date: 2120-05-07 09:17
Bus encryption flags: 17
Highest AACS version: 70

LibreDrive Information
Status: Enabled
Drive platform: MT1959
Firmware type: Patched (microcode access re-enabled)
Firmware version: 1.03
DVD all regions: Yes
BD raw data read: Yes
BD raw metadata read: Yes
Unrestricted read speed: Yes
If you are on Linux, flash the drive to BU40N 1.00 as 1.03-MK is buggy on Linux.
Cheers :D
----------------------------------------------------------------------------------------------------------------------------
For UHD enabled drives (AU/NZ/SG + Others) & DIY Single Drive Flasher (WW): https://uhdenableddrives.com
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

MartyMcNuts wrote:
Mon Sep 01, 2025 11:05 pm
steeledrum wrote:
Mon Sep 01, 2025 7:34 pm
I apologize if this isn't in the right spot. I've lurked all over these, but never posted until now.

I recently purchased an LG BP50NB40 (SVC NB52) and cross-flashed it using SDFtool Flasher with the BU40N DE firmware. I ensured the bootloader was checked this last time and verified in LibreDrive that the firmware is patched (microcode access re-enabled) with BD raw data and metadata read enabled.

Drive info shows Firmware version 1.03, MT1959 platform, and Highest AACS version: 66.

All-region DVD support and unrestricted read speed are active.

I’m able to read and rip standard Blu-ray discs just fine with MakeMKV, but UHD discs are not being detected. I suspect this may be due to my firmware version or microcode limitations. Anyone have any ideas? Let me know if you have more questions. Regarding the below, when a UHD is inserted, it just says no disk found. For what it's worth I tried with Atomic Blonde, Doctor Sleep, and Jurassic World.

Drive Information
OS device name: \Device\CdRom0
Current profile: BD-ROM
Manufacturer: HL-DT-ST
Product: BD-RE BP50NB40
Revision: 1.03
Serial number:
Firmware date: 2120-05-07 09:17
Bus encryption flags: 17
Highest AACS version: 70

LibreDrive Information
Status: Enabled
Drive platform: MT1959
Firmware type: Patched (microcode access re-enabled)
Firmware version: 1.03
DVD all regions: Yes
BD raw data read: Yes
BD raw metadata read: Yes
Unrestricted read speed: Yes
If you are on Linux, flash the drive to BU40N 1.00 as 1.03-MK is buggy on Linux.
Thanks for the reply! I'm not on Linux. My current workflow is ripping on my Windows 11 machine, and from there I copy the files over to my Plex server which is on Linux. Eventually, I plan to use only one computer, but as I learn things this is how I'm doing it. It is good to know that the firmware is buggy on Linux. I'll keep that in mind once I move over.

Any other ideas?
keydb_helper
Posts: 480
Joined: Fri Sep 06, 2024 4:47 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by keydb_helper »

steeledrum wrote:
Mon Sep 01, 2025 7:34 pm
I recently purchased an LG BP50NB40 (SVC NB52) and cross-flashed it using SDFtool Flasher with the BU40N DE firmware. I ensured the bootloader was checked this last time and verified in LibreDrive that the firmware is patched (microcode access re-enabled) with BD raw data and metadata read enabled.
You missed a step when you were flashing the firmware as the drive is still utilising the BP50NB40 firmware. This firmware cannot read UHD discs. For slim/portable drives only the BU40N, BP60NB10 and Buffalo firmware variants can read UHD discs.

Once it is flashed correctly the drive info panel in MakeMKV should list the firmware as BU40N and your drive will read UHD discs.
Public KeyDB Disc Submissions
  • LG/Buffalo/Asus drives only (Pioneer drives are not supported)
  • Please use file hosts, not forum attachments
  • If your disc dump is under 3MB, you need to manually include the MKB_RO.inf file from the AACS folder
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

keydb_helper wrote:
Tue Sep 02, 2025 12:37 am

You missed a step when you were flashing the firmware as the drive is still utilising the BP50NB40 firmware. This firmware cannot read UHD discs. For slim/portable drives only the BU40N, BP60NB10 and Buffalo firmware variants can read UHD discs.

Once it is flashed correctly the drive info panel in MakeMKV should list the firmware as BU40N and your drive will read UHD discs.
Can you elaborate on what I missed? I've attached how it looked when I did the flash.
MartyMcNuts
Posts: 3939
Joined: Wed Nov 22, 2017 11:45 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by MartyMcNuts »

steeledrum wrote:
Tue Sep 02, 2025 1:02 am
keydb_helper wrote:
Tue Sep 02, 2025 12:37 am

You missed a step when you were flashing the firmware as the drive is still utilising the BP50NB40 firmware. This firmware cannot read UHD discs. For slim/portable drives only the BU40N, BP60NB10 and Buffalo firmware variants can read UHD discs.

Once it is flashed correctly the drive info panel in MakeMKV should list the firmware as BU40N and your drive will read UHD discs.
Can you elaborate on what I missed? I've attached how it looked when I did the flash.
Yeah, I missed that too! This model must be cross-flashed to either BU40N or BP60NB10 to enable UHD readability (requiring 2 flashes). You have only completed 1 flash, which is the BP50NB40 1.03-MK firmware. This first flash removes the firmware encryption and does enable libredrive but this firmware is not UHD compatable.

You now need to perform the cross-flash to enable UHD readability. Please go to the SDFtool Flasher thread: viewtopic.php?p=94848#p94848 go to the section: to flash the BP50NB40 SVC:NB52 and follow from step 2. There's even a gif showing the process and there's no need to check the boot loader box at all.
Cheers :D
----------------------------------------------------------------------------------------------------------------------------
For UHD enabled drives (AU/NZ/SG + Others) & DIY Single Drive Flasher (WW): https://uhdenableddrives.com
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

MartyMcNuts wrote:
Tue Sep 02, 2025 4:10 am
Yeah, I missed that too! This model must be cross-flashed to either BU40N or BP60NB10 to enable UHD readability (requiring 2 flashes). You have only completed 1 flash, which is the BP50NB40 1.03-MK firmware. This first flash removes the firmware encryption and does enable libredrive but this firmware is not UHD compatable.

You now need to perform the cross-flash to enable UHD readability. Please go to the SDFtool Flasher thread: viewtopic.php?p=94848#p94848 go to the section: to flash the BP50NB40 SVC:NB52 and follow from step 2. There's even a gif showing the process and there's no need to check the boot loader box at all.
Thanks! I'll give that shot.
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

MartyMcNuts wrote:
Tue Sep 02, 2025 4:10 am
steeledrum wrote:
Tue Sep 02, 2025 1:02 am
keydb_helper wrote:
Tue Sep 02, 2025 12:37 am

You missed a step when you were flashing the firmware as the drive is still utilising the BP50NB40 firmware. This firmware cannot read UHD discs. For slim/portable drives only the BU40N, BP60NB10 and Buffalo firmware variants can read UHD discs.

Once it is flashed correctly the drive info panel in MakeMKV should list the firmware as BU40N and your drive will read UHD discs.
Can you elaborate on what I missed? I've attached how it looked when I did the flash.
Yeah, I missed that too! This model must be cross-flashed to either BU40N or BP60NB10 to enable UHD readability (requiring 2 flashes). You have only completed 1 flash, which is the BP50NB40 1.03-MK firmware. This first flash removes the firmware encryption and does enable libredrive but this firmware is not UHD compatable.

You now need to perform the cross-flash to enable UHD readability. Please go to the SDFtool Flasher thread: viewtopic.php?p=94848#p94848 go to the section: to flash the BP50NB40 SVC:NB52 and follow from step 2. There's even a gif showing the process and there's no need to check the boot loader box at all.
Marty, I have tried this multiple times to no avail. Now I'm concerned, as I cannot even flash to the 1.0 clean firmware you have linked from that link you sent me. For the life of me, I cannot get this to work. Any other ideas?
MartyMcNuts
Posts: 3939
Joined: Wed Nov 22, 2017 11:45 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by MartyMcNuts »

steeledrum wrote:
Tue Oct 07, 2025 2:53 am
MartyMcNuts wrote:
Tue Sep 02, 2025 4:10 am
steeledrum wrote:
Tue Sep 02, 2025 1:02 am


Can you elaborate on what I missed? I've attached how it looked when I did the flash.
Yeah, I missed that too! This model must be cross-flashed to either BU40N or BP60NB10 to enable UHD readability (requiring 2 flashes). You have only completed 1 flash, which is the BP50NB40 1.03-MK firmware. This first flash removes the firmware encryption and does enable libredrive but this firmware is not UHD compatable.

You now need to perform the cross-flash to enable UHD readability. Please go to the SDFtool Flasher thread: viewtopic.php?p=94848#p94848 go to the section: to flash the BP50NB40 SVC:NB52 and follow from step 2. There's even a gif showing the process and there's no need to check the boot loader box at all.
Marty, I have tried this multiple times to no avail. Now I'm concerned, as I cannot even flash to the 1.0 clean firmware you have linked from that link you sent me. For the life of me, I cannot get this to work. Any other ideas?
Then you are not following the instructions exactly!! Each file selection window tells you what to select in the title.

NO!! You should never use that clean 1.0 firmware!! That is for older models (pre 2016) that were flashed when they shouldn't have been.
Cheers :D
----------------------------------------------------------------------------------------------------------------------------
For UHD enabled drives (AU/NZ/SG + Others) & DIY Single Drive Flasher (WW): https://uhdenableddrives.com
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

MartyMcNuts wrote:
Tue Oct 07, 2025 3:29 am
steeledrum wrote:
Tue Oct 07, 2025 2:53 am
MartyMcNuts wrote:
Tue Sep 02, 2025 4:10 am


Yeah, I missed that too! This model must be cross-flashed to either BU40N or BP60NB10 to enable UHD readability (requiring 2 flashes). You have only completed 1 flash, which is the BP50NB40 1.03-MK firmware. This first flash removes the firmware encryption and does enable libredrive but this firmware is not UHD compatable.

You now need to perform the cross-flash to enable UHD readability. Please go to the SDFtool Flasher thread: viewtopic.php?p=94848#p94848 go to the section: to flash the BP50NB40 SVC:NB52 and follow from step 2. There's even a gif showing the process and there's no need to check the boot loader box at all.
Marty, I have tried this multiple times to no avail. Now I'm concerned, as I cannot even flash to the 1.0 clean firmware you have linked from that link you sent me. For the life of me, I cannot get this to work. Any other ideas?
Then you are not following the instructions exactly!! Each file selection window tells you what to select in the title.

NO!! You should never use that clean 1.0 firmware!! That is for older models (pre 2016) that were flashed when they shouldn't have been.
Apologies, as you're exactly right. I made progress last night after posting this and realizing what I had done wrong. This is now how it shows:

Code: Select all

Drive Information
OS device name: E:
Manufacturer: HL-DT-ST
Product: BD-RE BU40N
Revision: 1.00
Serial number: SIM21217L1554
Firmware date: 2116-12-20 15:28
Bus encryption flags: 17
Highest AACS version: 75

LibreDrive Information
Status: Enabled
Drive platform: MT1959
Firmware type: Original (unpatched)
Firmware version: 1.00
DVD all regions: Yes
BD raw data read: Yes
BD raw metadata read: Yes
Unrestricted read speed: Yes
Am I missing something else? It still will not read a UHD disk, and then when it tries to, and eventually fails, the drive seems to go unreachable. If I power cycle the drive, it then shows again. I read the guide a few more times, carefully. I don't think I'm missing anything that's not mentioned in it.
jinx100
Posts: 174
Joined: Wed Mar 13, 2013 5:58 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by jinx100 »

Clean your UHD disc or try a different disc. LG drives are not as good as Pioneer readers.

No insult intended but are you a bot? Your question about firmware on the BP50NB40 has been asked and answered probably 50 times before and a bot may just use those postings to make a realistic question.

"Clean your disc" has also been the answer 100's of times.
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

jinx100 wrote:
Tue Oct 07, 2025 1:41 pm
Clean your UHD disc or try a different disc. LG drives are not as good as Pioneer readers.

No insult intended but are you a bot? Your question about firmware on the BP50NB40 has been asked and answered probably 50 times before and a bot may just use those postings to make a realistic question.

"Clean your disc" has also been the answer 100's of times.
It's a brand new disc. I literally just took the case out of the plastic wrap. I'll still give it a clean. I'll try a different disc that's older. Perhaps it's something with the new one.

No, I'm not a bot. What a bot thing to say right?
steeledrum
Posts: 8
Joined: Mon Sep 01, 2025 7:30 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by steeledrum »

Apologies. Appears it was the disc.
jinx100
Posts: 174
Joined: Wed Mar 13, 2013 5:58 pm

Re: Cross-flashed LG BP50NB40 (NB52) – UHD not reading, Blu-rays are fine

Post by jinx100 »

steeledrum wrote:
Tue Oct 07, 2025 3:26 pm

No, I'm not a bot. What a bot thing to say right?
Nice pun!

What confused you in Marty's instructions about flashing the BP50NB40 drive? What changes could be made to make it more clear?
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