Looking at start-up preferences would be my first guess but you did that.

sudo sed -i 's/NoDisplay=true/NoDisplay=false/g' /etc/xdg/autostart/*.desktop

Apparently that command will display ALL startup application preferences. You could see if it is hiding in there. 

Bloughsburgh, that command does nothing on my system, unless I'm missing something. Am I supposed to get some sort of output in the terminal? Because I get nothing... 

I think that command un-hides the hidden preferences in the startup applications section you referenced. Try looking there now that the command has been ran.

That's about as much knowledge as I can provide. 

Thanks. It seems not to have un-hid anything that wasn't previously unhidden, though. Oh well.

Thank you very much for trying to help. 

The system probably seems to restore an old saved session and this has nothing to do with ram and probably nothin with autostart applications.

See if there are files in $HOME/.cache/sessions and try to move them away then reboot.

Restoring a session is done by your login manager which in Linux Mints case should be MDM if I'm not mistaken. Try too google for disabling session restoring. It's probably some old session config laying around in your homedirectory and would be fixable by moving these files away so the system regenerates them from a default one. 

I just rebooted and the problem seems to have resolved itself, but I have no idea how that happened.

I looked in ~/.cache/sessions as you suggested, but it had nothing except for a single .png image image file. After rebooting (with the system finally starting up again as it should) I looked again and saw a new .state file, which seems to have been newly generated; there was nothing like this when I last looked. So it's as you said it would be, only I didn't remove any old session config files...

Didn't manage to find anything on disabling session restoring via MDM.

In any case, thank you very much for all the information. 

I was just wondering, do any of you use anti-static precautions when swapping out computer parts -- in particular laptop parts? Is it crucial when swapping out an HDD/SSD, or are those things shielded already? How about RAM chips?

The internet seems to be full of very conflicting opinions on this, ranging from "it's the most important thing ever and you'll destroy your computer otherwise, often in insidious ways you won't notice immediately" to "eh, I build pcs for a living and do so in woolen slippers while rubbing a balloon on my head".

Also, lots of conflicting advice on what do do, ranging from effectively plugging yourself into the mains via a specially-made device (the instructions seem specifically aimed at people living in the US, though, which I don't) to touching the metal chassis of the computer once in a while (which doesn't help in the case of a laptop). Some say the former method will do more harm than good; others say the latter is completely useless. So I'm pretty confused and scared (which is the human condition, I guess).

So what do you do? 

Assembled boards are not as susceptible to ESD damage as their individual components are, but the risk is still there. The computer industry is a cut throat business. They wouldn't waste money on static protection packaging if it wasn't necessary.

If a computer has a power supply installed and it's plugged into a grounded outlet, then touching the metal case immediately before handling or installing parts may be good enough.

I always work on PCs in the kitchen where there is no carpet and frequently touch the water faucet to get rid of any static build up. Remember to only handle cards and memory sticks by the edges and stay away from the contacts. Never touch the pins on the processor.

Also, it's true that ESD damage may not show up immediately. 

I recently killed a raspberry pi by casting lightning from my finger tips. The danger depends a lot on your environment and clothes. Touch some grounded, blank metal (heating usually works). To be double safe, undress beforehand... ;) 

Wear rubber shoes with as little tread as you can, only stand on shagpile carpet, make sure that you lubricate the case with water for easier fitment of devices and Wear a tall metallic hate while building the computer in a lightning storm outside. 

 

Metallic Hate... is what just became Metallica :P 

if you can nab an antistatic bracelet thing, they are pretty handy... I put an alligator clip on the end of the wire and just stick it on something grounded. 

https://4.bp.blogspot.com/-M7xkWPxuWcQ/Vwopqa5sQNI/AAAAAAAAAig/JKATURv-9aM2IlxgstF0ptvKJ4A7bcpRQ/s1600/bolloxnvidia.jpg 

Why the hell is Nvidia even using Java? Nobody should allow that crap on their system. 

What the actual...? 

Finally managed to replace my cranky HDD with an SSD. Hopefully didn't break/damage anything in the process, though time will tell, I guess. Now I just need to reinstall all the stuff I had before (started over with a fresh OS install) and then I can finally get back to mapping... 

Make sure your alignments and TRIM are set up correctly 

Thanks! I was just about to ask if people have any advice on SSD-optimization on Linux. According to what I've read, Linux Mint 17.3 (which is what I installed) automatically enables TRIM -- is there a way to test whether this is the case?

What do I need to do with alignment? Is it too late if I've already started copying data over onto the SSD? 

Hey... Does anyone know if there's a way to fix led screen backlights not turning on? I can switch input modes a couple of times and that fixes it,.but if the screen is off for an extended period of time, the backlights don't turn on again until I switch modes again. 

likely a bad capacitor in PS. 

I'm having the same issue with my old as fuck 2004 monitor. Have to spend 10 minutes or so turning the monitor on and off again before it decides to stay on.

Fun times! Any recommendations for a cheap as fuck 2nd screen? Ie < �100 

If cheap is your criteria, you should be able to buy an Arduino kit with a LCD display (among lots of other components)... hard to beat that price :)