Hello. I am new to Zorin OS (and linux). I'm a teacher who has just set up laptops throughout my classroom and hoping to see an issue resolved. Some of my laptops (Mostly Toshiba Tecra but some Dell Latitude) will freeze randomly. Sometimes while the screen is on, in the middle of working, but more often when the screen has gone black after some inactivity. Usually once this happens, the fans start going extra time. None of the standard key commands work when this happens (even pressing num-lock or caps-lock doesn't change the light). The mouse usually doesn't work, but when it does, nothing is clickable. I am unable to use key commands to access terminal or lock screen. Only holding down the power button works. On the "About" page, I'm on Zorin OS 15.3, Intel Core i5-2520M, Graphics AMD Caicos, OS 64-bit. As I am new, please keep things simple for me. I have read as many other threads as I could, but nothing seems to be exactly my case. Thank you very much in advance. This addition of technology is amazing for my students, but frustrating when it freezes during a lesson.
Hello and welcome to the forum 
If you have enough RAM, you might hit a better luck with a newly released Zorin 16.
Hello. Thank you for your reply. How much safely be enough? Most of my systems have 4GB ram. They are also quite old units (not sure exactly but were converted from windows 7). Lite seemed to be what was recommended for older models. Is there an education lite 16 available?
Coming Soon (TM)
We all are waiting impatiently for the release of Zorin16 Lite.
I myself need it for my 10 years old Acer Aspire.
For 4GB RAM, I think it is better you stick to the Lite version. Gnome desktop would be too heavy.
Great! I will anxiously await its release Thanks for the info
In the meantime, are you aware of any settings, downloads, upgrades, or anything that may help stop these freezes?
Good question.
I have been using Zorin 15,3 Lite on the aforementioned Acer Aspire, but mine is rock solid. I'll ask other volunteers. They might have some idea.
@Aravisian @tomscharbach @337harvey
Thank you very much for your support. I look forward to hearing what the others have to say
On those machines, Zorin OS 15.3 Education Lite should work fine and is supported until April of 2023.
As FrenchPress pointed out, a common cause is filled RAM. At 4 gigs on 15.3 Lite, you would need a lot of Browser tabs all open and running at once to do that...
Another is Battery on notebook computers. If the battery is failing, it can cause the battery monitor to be unable to make the correct detection. Some resolve this by disconnecting the battery and running the notebook as simply plugged in - or replacing the battery. Replacing or removing the battery should be done only if the battery tests as bad.
With Administrator Privileges, you can check the /var/logs/ for log files (You can use pastebin to post them here for help reviewing them. They can get quite lengthy).
To Access through GUI:
Open terminal with ctrl+alt+t
Enter in:
pkexec thunar
Click the UP arrow icon on the top toolbar to the topmost level that is Root (/). Here, you will see /bin, /dev, /etc... and /var
Click open /var then /log and scroll down to the text file:
xorg.log
dpkg.log
kern.log
syslog
Start with Syslog and xorg.log.
Hello, thank you so much for your response. I've just opened up one of my computers. After opening terminal and entering the command, it says "Cannot run program thunar: No such file or directory".
I'm sorry if I'm not understanding or doing something wrong. So, with that said, I went to the "files" application and found the folder /var, then /log. In this file, I have syslog, dpkg.log, kern.log but no xorg.log. I'll work on copying over syslog for you to look at. Just a moment...
Thank you for your help
I am sorry. Are you using Zorin OS 15.3 Core? Lite or Education Core or Lite?
I am fairly sure it was lite. I got these laptops from a non-profit who refurbishes laptops for schools so I think they would use the type appropriate for older models. Is there a way through terminal or something I can look up which type of zorin I have?
Sadly.... chuckle... this is a point of contention about 15.3 that we have all raised: There really isn't an easy way.
Most of us can tell by looking at the desktop but, for someone new to Linux, it is not that recognizable.
Please open a Terminal and type in
nautilus
If files launches, you have Core.
In terminal enter in
xfce4-appfinder
If it says, "Not installed but can be installed with..." - then you have Core.
Just typed in nautilus. Files did appear with a popup - "oops, something went wrong. Unable to create a required folder...
and in the terminal, a variety of warnings appeared
just typed in the second command and it says command 'xfce4-appfinder' not found but can be installed with:
So this means they used core... could this be the cause of my problems? The refurbisher failed to choose the correct zorin?
It... actually could.
The Random Freeze is far more prevalent in the Gnome-Shell (What Core uses) on certain machines than it is on the XFCE desktop.
And on those machines, I would definitely recommend the Lighter Desktop. Gnome is not more advanced than XFCE and XFCE has all the same (if not more in my opinion) functionality.
Is reinstallation an option for you? That is a lot of machines...
Oh goodness, yes that will be a lot of work. Yes, it is an option but I'll be putting a few late nights in at the school. I've got some required apps too which will need to be reinstalled (chrome, arduino ide). Just checking, there isn't a way to change OS versions without reinstalling? (I'm guessing no... 'weeps in corner')
I can definitely try mixing for experiment's sake. Excuse my lack of knowledge (im pretty new) what is cinnamon? (in relation to linux)
Ah, I don't agree.
XFCE is as lightweight as LXDE is.
Cinnamon is heavier than XFCE, but lighter than Gnome.
tbuller, on Windows, you have one desktop environment: Windows.
On Linux... There are many. Many to choose from and each has its pros and its cons.
This type of variety is a beautiful thing but it can be overwhelming when you first encounter it.
What about replacing only the Troublesome (freezing) computers?
Lastly... Sorry Harvey but I disagree again... Zorin OS 16 Core is indeed fast with much improvements made on performance, just as 15.3 was much faster than Zorin OS 12.4 was. But... These are in relation to the previous Core (Gnome) desktops. On these older machines, it wouldn't really be that much benefit and may be worse. I have two similar spec machines here.
Even improved Zorin 16 Core is not going to perform better or faster than Lite on a low spec machine.
Thank you very much for taking the time to explain things. Fingers crossed, some of my tech-ier students won't mind helping me through the process now, and then again when education lite 16 makes its debut. After converting, if I'm still having similar issues, I'll return to this thread and perhaps there will be some clues in the logs. But fingers crossed doing this changeover makes all the difference. Thank you again!