I have E580 20KS006HRT model. Some time ago the problem described in the subject started occuring periodically. That is, I can go into BIOS, I can select boot device, but instead of actually booting the laptop hangs infinitely with black screen and blinking cursor (_ symbol). After performing several reboots and random actions (plugging in/out devices) the system booted. This is definitely not a problem with the booting devices themselves as they (e.g. USB stick) boot perfectly on other computers.
Today the laptop refused to boot at all. This time numerous random reboots didn't help, so I started googling. The following issue:
https://support.lenovo.com/us/en/solutions/ht079465
looked similar, though for different machines. Indeed, disabling bluetooth helped to boot one time. The next time most often I must disable it again (though it is already disabled), otherwise familiar black screen appears. Issue also says I should upgrade BIOS, and that's what I'm going to do. My current BIOS version is 1.24 from 2018.08.24, and the latest one is 1.35.
Unfortunately, I failed to do this quickly due to kind of chicken or the egg problem: I use only Linux (no Windows on disks), so to upgrade I must either boot from special BIOS update ISO or install Windows (which also means booting from USB with ISO). However, the laptop fails to boot (even after disabling bluetooth) either Windows and BIOS update image from USB stick, though with different symptoms than described above -- it just refuses them: if there is any other (than USB stick with BIOS update/Windows) boot device enabled, it goes ahead to it, otherwise returns to boot selection menu. I've tried all USB ports. I don't know whether this problem is related to the root issue, however I'm sure again that this is not a problem of USB stick because it boots okay (at least with BIOS update utility) on another Lenovo laptop.
I have another USB stick with live Linux which suprisingly successfully boots. This is my special mobile stick with some persistent data, so I don't want to overwrite it with BIOS update tool. I'm going to find and try some third stick to boot it, hopefully this would help.
I'm writing this hoping to help anyone struggling with the same issue and hear from someone who already had had it.
As an offtopic, generally I'm totally disappointed with E580 quality. In a week after purchase some keyboard keys died (the laptop ignored shift + t, shift + y and some other keys). The shop replaced the machine with a new one. A couple of months later sound disappeared. They replaced the sound card on the warranty. Earlier another minor issue emerged: sometimes, not very often, after changing sound level with f2-f3 keys the keyboard freezes -- laptop ignores all keys; after pressing f2 or f3 again keyboard works again. This wasn't repaired during sound card replacement because it is hard to prove existence of the problem as it occurs rarely. And now this issue...