I have a brand-new HP ProDesk 600 G3 Microtower PC that I wanted to use for Kubuntu 16.04 LTS, but I'm having a strange problem.

The Kubuntu LiveCD ran normally through the installation process. Reboot proceeded normally, with the Kubuntu logo appearing on the screen. But this is where the problem arises: after that, NOTHING ELSE shows up on the monitor screen. It's as if the video signal had been lost, but the monitor doesn't complain about losing the signal: it simply stops showing me anything.

The monitor is a Hannspree HF205 and comes with DVI and VGA ports. The DVI port is in use by a Windows computer without issue. Before this, the VGA port had also been running fine, providing video for another Windows PC (DVI port from a GPU to a DVI-to-VGA adapter, then VGA cable into the monitor).

The ProDesk came with two DisplayPort ports and I bought a Rosewill DP-to-VGA cable to connect into the monitor's VGA port. The computer had FreeDOS installed and everything worked fine, but when I tried to install Kubuntu the process seemed to move forward (the light on the HDD was blinking), except that I couldn't see anything on the screen. So I installed a GeForce GTX 1050 from MSI that comes with DP, HDMI, and DVI ports, then plugged the adapter into the 1050's DP port, and ran through the OS installation process again. The computer POSTs fine (I can get into the startup menu), and I could see everything Kubuntu wanted to show me during installation, but after reboot the display disappears soon after the Kubuntu logo.

I'm hoping that someone with experience with this sort of thing will provide guidance. Thanks in advance.

Are you able to get to a terminal?

CTRL-ALT-F1

?

Looks like I can, kind of. I hit those keys and reached a login command line. But the display is blinking annoyingly, and the computer won't register what I type while it's blinking.

Separately from login issues, I was going to add the following bit of information: when Kubuntu is in that "no display but monitor live" state, if I press the power button the Kubuntu logo comes back briefly, then at the top of the screen there's some numbers followed by the words "reboot: power down." Hope this helps in tracking down the problem.

What type of connection are you using? HDMI, DVI, VGA?

Can you try passing the kernel nomodeset from Grub2?

Something like this..

linux /boot/kernel nomodeset

Another one to try is....

linux /boot/kernel video=800x600

I've tried connecting to the VGA port on the monitor the following ways: 1) onboard DisplayPort (before the GPU was installed); 2) GPU DisplayPort; and 3) GPU DVI.

Since I can't log in due to the blinking display, unfortunately there's no question of entering any commands. I may re-install Kubuntu again just so that I can enter a single-character password, to make it easier to log in.

At some point, I tried loading a Mageia 5 Live CD from Linux Format magazine, to see if that one would display properly. It, too, failed, but this time I got an substantial list of messages. I wanted to attach a screenshot (smartphone photo) in case it helped us to figure out what's going on, but the original picture is 3.7MB and I could only reduce it (even after cropping) down to 355KB, while the maximum file size for attachments here is 256KB.

How about nomodeset?

Thanks. At what point in the process would I enter that command?

Within Grub2

You can edit a menu entry by typing "e"

then look for the line that starts with linux

usually something like this....

linux /boot/vmlinux*****

you need to navigate to that line and at the end of it type "nomodeset"

linux /boot/vmlinux**** nomodeset

Then press F10 to boot into that entry

Let me know how it goes.

What graphics card is present in the computer? I'm aware some computers have issues due to having graphics cards that have ugh support for Linux.

I figured out that I had to keep the ESC key pressed after POST and before the Kubuntu splash screen came up, then I was able to get a "grub>" command prompt.

At that point, though, typing "e" (with or without the quotation marks) just gives an error saying there is no such command. And typing "linux /boot/vmlinux**** nomodeset" followed by the F10 key, didn't do anything.

I am really new at this and am not even sure that I ever reached the Grub menu, all I saw was a notice at the top about the Grub version, some language about minimal BASH, and then the grub> prompt. Nothing about menus, or lines in the Grub configuration file, or how to navigate to them.

Help!!!

Grub2 Manual

https://www.gnu.org/software/grub/manual/grub/grub.html

There are 2 modes in grub.

Command Interface and an edit for the menuentry

When your in the command interface...

try pressing ESC key once.
Then press "e"

That should take you to the editor for the menu entries.

If you get that far, paste all the information from the default menuentry here.

It's a GeForce GTX 1050. If you need the info, the first post up above has a link to the exact model I bought.

But note that I was having the problem even before the graphics card went into the computer. In fact, the reason I put it in is that I already wasn't getting any display off the Live CD past the "Try Kubuntu" screen.

I'm wondering if the issue has to do with this DisplayPort stuff, the computer came with two of them and no other kind. Since the graphics card has not only a DP port but also DVI and HDMI, my next move will be to try connecting the computer to the monitor via an HDMI-to-VGA adapter.

Thanks for the manual, I'll check it out.

Pressing ESC behaved like the Enter key: it went to a new "grub>" line before I got to do anything else like typing "e". I tried keeping ESC pressed, but that just gives me more new blank grub> lines, exactly as if I kept hitting Enter.

Please paste a picture if you can.

Reading around the Grub manual, I saw this:

>>GRUB looks for its configuration file as soon as it is loaded. If one is found, then the full menu interface is activated using whatever entries were found in the file. If you choose the command-line menu option, or if the configuration file was not found, then GRUB drops to the command-line interface. <<

So I'm thinking that there may just not be a configuration file present, since I'm not getting an option to choose between command-line or menu interface, it's taking me directly to the CL.