Good stuff, includes some tricks I hadn’t known about and will have to try.
But how should all the key sequences involving function keys (e.g. Ctrl-Alt-F2) be interpreted on newer keyboards on which you must press the Fn Key to get the function key action with something else happening if you don’t?
So far, no crashes. 
Also, way back up at the beginning of our conversation you suggested:
I never got around to trying #1 but now, when a return to a suspended screen pressing CapsLock is the first thing I try. I’m not sure why you suggested it but it seems like a good and harmless thing to do.
I haven’t tried #2 in a crash situation. I just tried it now (again, non-crash).
CTRL+ALT+F1 (actually it’s CTRL+ALT+Fn+F1 on my system) blanks the screen. Then CTRL+ALT+Fn+F2 brings up a login screen, but once logged in, everything that was open before is still open. Nothing happens on CTRL+ALT+Fn+F3.
Ah, sorry. It’s a way to detect if the kernel has completely crashed, or if it’s “only” the GUI. If the entire Linux kernel has locked up, you won’t even be able to toggle the caps lock light on and off.
If the caps lock light is still operational after a lock-up, then it points to possibly something in the GUI stack, typically. So it’s a good way to do a quick sense-check.
I refer back in time to post 17 of 21 here.
I don’t know yet how to easily cross-refer/link between posts (numbered in threads) across multiple threads.
Anyway the idea was to explore Input Remapper. Seems to map the issue above (in post 20/24).
P.S. I received my first Link notice, so cross-linking now better understood. Saves a lot of hassle.
### First Link
This badge is granted the first time you add a link to another topic. Linking topics helps fellow readers find interesting related conversations, by showing the connections between topics in both directions. Link freely!
Sigh …
Still a problem with using bluetooth. Not a system crash anymore (thank heavens) , but I have noticed the mouse losing its scroll wheel functionality while running. The mouse still works but not its scroll wheel. The only way I know to get it back is removing the device from settings. This only disconnects it, doesn’t unpair it, so I have to wait for it to fully disappear, then I can add it again and the scroll wheel works.
I see two possible solutions:
Anyone want to hazard a guess as to what might be going on here?
I’ve been sort of peeking at this thread as it gets updated but not playing super close attention. Sounds like the issue must boil down to something with your mouse or Bluetooth. I would definitely be looking in your journal and /var/log/Xorg.0.log for errors when the scroll wheel function drops.
Meanwhile, the command line tool you want is called bluetoothctl, It’s interactive, so just run it and you can see how to use it by running help.
Also: as the owner of several Logitech mice, I find they Just Work™ so I don’t see the value of Solaar in general. It is not a device driver, so it’s not going to add much. Maybe if you have a really special device (like the Ultrathin Touch Mouse I have), it might expose some additional configuration parameters, but I wouldn’t bother with it unless it is clear you absolutely need it.
Thanks, but now I have more serious worries. See below.
Grrrrrrr!. I’d been crash-free for a couple of days and decided it was now time to run the program for which I’d bought this laptop in the first place: PixInsight. It’s a very complex astrophotography program that would not run on my 10 year old laptop.
Result: a crash during the first session I’d run it with.
journalctl --boot=-1 | tail -n 500 | pastebinit
https://paste.ubuntu.com/p/bNGHt8BtNB/
PixInsight is mentioned there. Going to have to contact them about this. Just paid for the commercial edition of this application. Let no good deed go unpunished.
But might anyone here have any ideas where I should look?
I think what you said above is your best bet.
If you want to look more carefully at this issue, we need more lines in that journal than you have. Essentially from where there was no problem on. To do this:
journalctl --boot=-1 --since=12:59How would I send that to you? Pastebin will not take it and this site doesn’t accept file uploads.
I could put it on Google Drive.
Did pastebinit complain about it being too long? You could try using a different pastebin. pastebinit -l will give you a list of supported ones and then you can use it with -b e.g. pastebinit -b pastebin.com.
Thanks. I found one that worked:
journalctl --boot=-2 --since=12:30 | pastebinit -b paste.ubuntu.com
https://paste.ubuntu.com/p/H59Rym7mfK/
I’m potentially having similar issues with a Lenovo IdeaPad Slim 5 (14IRL8). Hardware acceleration in Chrome/Chromium causes a lot of hitching and lag. Also, when I leave the machine and come back to it, the trackpad takes a while to respond.
Actually… That’s a general protection fault. That raises one possibility: bad memory. I’d try running the memory test from a live image (note: this requires BIOS/legacy boot) and see if you don’t have issues. That would explain a lot.
Running “the memory test”. Would that be the memtest option on the boot screen? I can certainly try that.
However, the Pixinsight folks say I don’t have enough “virtual memory” (swap) enabled. Their program is a hog. The machine came with a 66GB swap file, not a partition. I’m thinking of creating a swap partition using GParted (off a USB stick boot). If I do that, what should I then do with the swap file?
Enable it:
sudo swapon -a
Recheck with;
swapon -s
Yep. If that succeeds your other comments make me wonder if you simply don’t have enough RAM for what you’re doing regularly.
I’m fairly confident you’re not going to see any performance gains doing this. But 66GB isn’t enough swap for them? Jeez this program sucks. XD How much do they want you to use???
@wxl said it all, no gain. 
Sounds to me this program will take a Monster System to run it.
They suggest 128 GB.
I thought I bought one. And maybe I did. But it needs its swap. Probably should have bought more RAM.
In fairness to the program, it does a lot. But the jury is still out on it for me.