Black screen on boot/installation Zorin OS 15.1
 

Hi. First of all, I'm new in Linux, so sorry for possible dumb questions.
I had black screen (no signal according to the monitor) when tried to install the Zorin os first time. Before it there was dull display of warnings but it was so quick, I could not read it. After the number of restarts install began like it should and I get the system working.

I have no issues at all after the boot, but if I boot roughly 50% times I have the same black screen (without any warnings) and have to press reset. I tried to see something at logs at the settings but could not find anything related. (Once again, I'm new to this and may be missed something). The GPU is AMD Radeon (does't remember exact model)

What can I do with this?

Thank you.

Given that Zorin is a paid OS, have you contacted their support channels?

More will support the "free" (as in money) systems (here) faster as we'd have to buy a copy of Zorin just to know what they changed..

That being said, you would need to be looking through the Xorg.log file in /var/log for an indication as to the cause.

To flesh out phantom cyph's post a little:

Linux logs just about everything. Most of the logs are cumulative but the Xorg log is not. It represents a single attempt to get X up and running. The previous log is also stored as Xorg.log.0. So if you have a successful boot after an unsuccessful one, look at the ends of both these files and see where the previous unsuccessful one broke off. My guess is that it's a video driver problem.

Also when you get the black screen, is your keyboard alive? You can check by putting down the caps lock and seeing if the indicator light comes on. If you have a working keyboard, try pressing ctrl+alt+F2 and you should see a login prompt. You can log in there and examine /var/log/Xorg.log.

Ok, I promised the dumb questions so here is one. I couldn't locate xorg.log file inside /var/logs/
Here is the screenshot of what I have.

Speaking about the paid Os, I don't have it. I use Zorin core which is free.

Sounds like Freespire/Linspire all over again... :)
It's /var/log not /var/logs..

While "logs" would make more sense in English as it stores multiple logs therefore making it plural, Linux is a very programmer/developer centric system. As such it uses the programming nomenclature, lowercase and always singular. It reduces confusion in the long run because in reference it would be seen as "/var/log/Xorg.log" rather than "/var/logs/Xorg.log" which gets confusing as you're seemingly selecting a singular object from a "plural" location.

Did you look at the attached thumbnail? That's /var/log all right. And the OP is right, there's no X log. Which means that it is not even starting X. That is seriously weird.

If it crashed earlier in the boot process, surely you should get thrown back to console 1 with some messages.

Yeah.. West Africa isn't known for it's decent WiFi connections, so text logs help.. as such I generally avoid screenshots/image downloads.

I did however look at the screenshot this time as it sounded odd that it's missing a xorg log. I'd recommend checking "faillog","boot.log", "lastlog" and the "kernel" logs.. the last one is interesting as (just looking at my install), I have none.. so their creation could indicate an issue which required logging..

If you want to try and search these log files easily, open a terminal in that folder and try something like:
or And it will bring back files which mention them. That may give a better indication of what's going on. If Xorg isn't even starting.. that seems odd and it's going to be logged somewhere else.

Thanks, I'll try it.

Ok, I tried.

returned this two strings from the each boot

Doesn't look like any error.

returned the following

So, I located the Xorg.0.log inside /home/.local/share/xorg/
I didn't find any error there. What should I look for?

I noticed one additional thing. Inside /var/log there is file kern.log Looks like there is nothing inside it about unsuccessful boot but I can see that at each susscesfull boot I have the same error

And this string repeats itself many times. I tried to google it but didn't understand anything except this seems to be connected to the some Bios issue. May be this is my problem?

And, to clarify things, when the problem happens the keyboard doesn't work. And it's not just black screen, there is no signal going to the screen.

ACPI errors aren't usually significant. They arise because most computers use the Microsoft version of the ACPI control language, which is often incorrect in its syntax and the Linux kernel doesn't like that. Kern.log btw is the output of messages from the kernel.

The Xorg log is in your home directory and not in /var/log because you have a distro that runs X in your name and not as root. That's not traditional but some modern distros do it. Look at the end of the file. If there is a break, that's where it will show.

This may sound patronising, but have you checked your physical video connection? Both ends of it?

it appears you have hybrid graphics.
try this as root edit your /etc/default/grub and change this line to this then run reboot. If it makes things worst at the boot menu e to edit, find the fbcon:map=1 on te line that begins with Linux and delete it. Then reverse what was previously done.

Ok, I'll try it, thanks.
Meanwhile, I looked at Xorg.log.old file and I saw something at the end. Which is not at Xorg.log I guess, that Xorg.log is the last successful boot, and the Xorg.log.old is the previous unsuccessful?
Here is what is at the end of Xorg.log.old:

Needless to say, i have absolutely no idea what that means.

Tried it. Didn't felt that it did anything. Two times I had the same issue, from the third time system booted successfully. So I reverted the changes.

you need to post the whole xorg.log file

I don't know if there's any point in that. The end shows that it closed down successfully, presumably at system shut-down. If it had broken at some point, it would have ended at the break. At least that's always been my experience with X logs.