> I had a similar problem some time ago (getting a blank screen in the
> Debian 9.3 installer), also with a Lenovo laptop. I was able to solve
> the problem by going into the BIOS and under startup options changing
> the "UEFI/Legacy Boot" setting to "Both."
Thanks for the advice. Unfortunately, no such option appears available in my BIOS version. I tried setting an administrator password, which does unlock a few more options - for instance to disable Intel SGX, but that didn't help.
It's working in Ubuntu, but that seems to be using a different way to install altogether. I'm wondering if I could replace the kernel d-i uses with the one from the Ubuntu installer for instance, or if there are any options I should add to the vmlinuz line in Grub.