I was trying to load Lineage onto an old One M8, I had just cleared the system, cache and data partitions using TWRP. I then clicked reboot, which I now realise was a mistake. I am now stuck on the HTC logo screen, none of the physical buttons are responding, so i cannot get into bootloader etc.
The physical buttons
will respond, but you need to hold them for a pretty long time in the current "stuck" state. Do this:
1) Hold vol up button and power button, until the phone restarts (may take about a minute in the current stuck state).
2) Once the screen goes dark to reboot (but
before the HTC logo screen appears again - I think you have 5 seconds or so), let go of the buttons, and
only hold the vol down button. Do
not let go of vol down, until you see the bootloader screen.
3) If you fail to get to bootloader, you simply got the timing wrong. Either started pressing vol down too late, or you let go of it too early. Simply repeat steps 1 and 2, until you get to bootloader.
4) Once in bootloader, simply select recovery, which will boot TWRP. And flash Lineage as you originally intended.
A note on wiping system when flashing a ROM: I know some folks will swear by this, and some guides will tell you to do it. But it is not necessary, and as you've seen can cause some complications. Nothing that isn't easily solved, but may give you headache nonetheless (like this case here).
The ROM install script will wipe system before it installs the custom ROM. So doing it yourself is redundant. And in the case of the ROM fails to install (it happens) you are stuck without a working OS. My recommendation is only to wipe cache, Dalvik and data when flashing a custom ROM (the default wipe in TWRP).
Any perceived "benefit" from wiping system is usually a placebo. In the rare event that the custom ROM fails to boot (or some other issue), you can always go back and flash again, wiping system (as a troubleshooting measure, etc.). Of the years of flashing ROMs (dozens and dozens of times) on various Android devices, I can count maybe 2 times where I felt I needed to wipe system when flashing a custom ROM.
I can't send ADB commands to it, it won't show up on windows file explorer
This can be expected when "stuck" on the logo screen. adb will only work when booted to a working OS, or alternately when booted to TWRP. Same thing with MTP access (File Explorer).
