Hello there,
I'm very new to LinuxOS but also I'm facing problems now.
I couldn't manage to do that.
I hope to know how to recovery and what occurs inside PC.
Please, help me.

[Problem]
Monitor displays nothing("No signal" message) after I selected any Kernel to boot.
the problem occurs when I boot any Kernel, Rescue mode, CUI mode.
I tried to boot from DVD media but also the result is same.
only grub2 console works on my PC.

[Suspect]
Before the problem occurs, I created "/etc/X11/xorg.conf" file by force in order to change resolution.
After that, I conducted grub2-mkconfig and reboot but PC didn't up again.

[OS version]
Centos7 (kernel:4.4.179-1.e17.elrepo.x86_64)

[Hardware]
Model: TOSHIBA REGZA PC D711/T3EW
CPU: Intel Celeron B815
Graphic Card: Intel HD Graphics

Try this:

1. At grub menu, strike E key
2. move cursor to end of line that begins with linux
3. remove, if present, splash=silent
4. append a space and an S or a 1
5. proceed to try booting

If successful you will be presented with a shell prompt from which you could remove or rename xorg.conf before trying again a normal boot.

If it fails, try same thing, but add also to linux line plymouth.enable=0 before proceeding

remove that file.
once you can boot again, we will talk about how to change resolution.

1 members found this post helpful.

You can try booting a "live" system, then mount your CentOS root filesystem, then remove xorg.conf

Based on what you've said; it booted up before you tried changing your screen resolution? Then when you edited/created xorg.conf you got the "No signal" message?

Why did you run grub2-mkconfig ? You only need to do that if you make changes to GRUB's configuration, so I'm not sure why you've done that. This could actually be the problem instead, depending on exactly what you've done. I think we need to verify if it's your edits to xorg.conf, or in-fact what sounds like your edits of GRUB's configuration. What did you change in GRUB's configuration?

Also, have you ever been able to actually boot any kernel ? Has kernel 3.x ever worked ?

I think it's worth noting that "No signal" message is very likely coming from your monitor rather than the operating system/computer.

Thanks for all.

This is a supplementary information.
Firstly,why do I run "grub2-mkconfig" is:
I wanna configure resolution as 1920x1080 but there is not appeared in kde system setting.
I tried to run xrandr but xrandr said "display unclaimed".
So, I installed intel-graphics-driver into centos manually and change target of driver to use(by xorg.conf and grab.conf).
But these files didn't exist.
Then, I created xorg.conf.new newly and rename and put it under X11 directory.
And, I guess OS is able to run because PC was rebooted when I strike "reboot".

Dear mrmazda
Thanks for your reply.
I tried your suggestion but as a result of those steps, I'm very sorry, I couldn't solved the problem.
Now also displayed "no signal" message after Kernel loaded.

Dear ondoho
Thanks for your reply.
As you said, I want to remove xorg.conf but I can't reach /etc/X11/ directory because of CUI doesn't up.

Dear jsbjsb001
Thanks for your reply.
The reason of run grub2-mkconfig is above written.
As you said, "No signal" message is coming from monitor.

xorg.conf can be removed by booting installation media into rescue mode or boot from HD mode, mounting the / partition (if not already mounted - execute df or mount to check if it is), then deleting it.

Dear jsbjsb001, nrmazda

I'm sorry, I had confused centos livesystem and install media.
Live CD is not here, and I can't create it now.
I will make CD & try boot from it, so please wait while few days.
Excuse me.

You don't need to "make" it, you can download a live ISO from a CentOS mirror, like this one. Also, any live Linux distro should let you do what you want to do - it doesn't have to be CentOS if you just want to mount your root filesystem and delete a file.

Also, you have not answered the question about GRUB; did you change anything related to GRUB ?

I'm sorry for my late.
I tried to boot from live-CD but I couldn't mount root file system because of partition error.
now, I re-installed centos and it works well.

> jsbjsb001
excuse me, I didn't answer to it.
I didn't change any grub.conf files manually, I only ran "grub2-mkconfig".

thank you all.