Around half the time when I open the lid, the screen is blank and won't respond to keyboard/mouse input. I've already looked through all the forums and nothing I tried has worked. I've also recently reinstalled Ubuntu, so I'm pretty sure it's not something I installed.
For reference I'm using a Lenovo Thinkpad X1 Carbon 6th gen on Ubuntu 18.04.
Interesting: The keyboard backlight responds (Fn + space) and the FnLock light turns on and off, but the only way to use my laptop is to force reboot by holding the power button.
This small but plaguing issue is seriously making me consider switching to Windows/Mac 🙁
Best Answer
I had the same problem on an old Thinkpad SL510: suspend would leave the machine with a blank screen (but the fan was still on, so it was not a proper suspend) and only force-reboot would work.
Running
PM_DEBUG=true pm-suspendproduced a log without anything suspicious (all sleep.d scripts reporting "success").Uninstalling package "tlp" (which also uninstalled "tlp-rdw") fixed the problem.