new LG BU40N slim drive help needed please

[burtybasset]

I have been reading through the forum for the last week and have purchased an LG GU40N slim drive as that is one of the supported drives I could find in stock somewhere. I have also purchased makeMKV in the hope I can rip some UHD discs. It has come with firmware 1.05 and I have read these are tricky to downgrade but it is possible but I may need to sidegrade first ? I have loaded the GUI tool and downloaded the suitable firmware but just get an error when I try to flash. I am out of my depth and would appreciate someone pointing me in the right direction. Thanks in advance.

[Billycar11]

see guide below i tested with 1.05 works fine downgrading to 1.03mk with enc

[Collyde]

I only see the fw HL-DT-ST-BD-RE_BU40N-1.04-NM00500-212005061142.bin in your pack.
Is that actually v1.03?

[Coopervid]

I only see the fw HL-DT-ST-BD-RE_BU40N-1.04-NM00500-212005061142.bin in your pack.
Is that actually v1.03?

The firmware is in the OLD folder.

[Collyde]

I could flash LibreDrive 1.04 on a newer drive with v1.04 from the factory.
But 1.03 from the old folder would not work. It flashed without error, but it stayed on 1.04. I used the 'enc' option

[burtybasset]

Thank you for your help. Once I had found the correct version firmware 1.03 in the OLD folder all worked fine and drive reading UHD discs fine !