BU40N shenanigans: won’t read a particular disk unless I unplug the data cable first

[Amogus]

So I have this BU40N flashed to 1.03 I bought from eBay, it’s in an external enclosure with an attached data USB cable and an additional port for power. For some reason, I have a particular Bluray that will not load at all under normal circumstances. Makemkv sees that it tries to load the disk, and you can hear the drive run at a lower speed for maybe 3-4 consecutive runs before it gives up and nothing appears on the computer. However, if I unplug the data cable and only leave the extra power cable plugged in, I can then wait until the light on the BU40N stops flashing and plug the data cable into the computer. Without fail the disk will show, and I can then do a full BDMV backup or play back the episodes without checksum failures or skipping. Is this a problem with the Bluray disk or the drive itself? I’m confused because it seems to work fine but I have no second drive to test with and I would like to sell this disk at some point but don’t know if I can label it as working.

None of my other 12 disks seem to have this issue.

[MartyMcNuts]

So I have this BU40N flashed to 1.03 I bought from eBay, it’s in an external enclosure with an attached data USB cable and an additional port for power. For some reason, I have a particular Bluray that will not load at all under normal circumstances. Makemkv sees that it tries to load the disk, and you can hear the drive run at a lower speed for maybe 3-4 consecutive runs before it gives up and nothing appears on the computer. However, if I unplug the data cable and only leave the extra power cable plugged in, I can then wait until the light on the BU40N stops flashing and plug the data cable into the computer. Without fail the disk will show, and I can then do a full BDMV backup or play back the episodes without checksum failures or skipping. Is this a problem with the Bluray disk or the drive itself? I’m confused because it seems to work fine but I have no second drive to test with and I would like to sell this disk at some point but don’t know if I can label it as working.

None of my other 12 disks seem to have this issue.

Not the drive, the enclosure. You could also try cleaning the disc. The drive/enclosure might be struggling to read that disc and run out of juice. You could also try using the drive out of the enclosure by means of an AC self-powered SATA to USB adapter with a slimline sata adapter.