I am in a pickle with this relatively new installation of Kubuntu 14.10. Not knowing where to start, I will go from the beginning.
I installed the system a few days ago. Everything installed fine and worked almost perfectly. Almost because for some reasons, after the system booted, the writing was so small that I could not understand them, even after changing the resolution to the lowest possible. After a reboot, everything went to normal.
For a few days the system worked magnificently, until today, after leaving the PC on at lunch, the system froze and I had to hard reboot. Since then, the screen goes black every time that the HDD icon appears on the screen (hence loading the 1920x1080 resolution).
I tried to boot in recover mode and remove the NVidia drivers, then resume the boot. The system boots normally at a lower resolution. As soon as I restart the system, the PC goes back to HD, and the same issue happens (screen shuts off during HDD icon).
The driver in use is the native NOUVEAU. If I try to re-install (via GUI) the Nvidia driver, the same problem stays.
This situation happened in this same PC a couple of months ago when I tried the same installation.
I did install Kubuntu 14.10 on other 2 PC (one with Nvidia 7800GT graphic card) and there it works normally.
This system graphic card is a GT610 Nvidia and I am using the HDMI as output.
What baffles me is that it worked for a few days, then it stopped.
Edit #1 - I did extensive research on different sites, but I haven't found a working solution for this problem. Most of the problems I read, tell that the screen doesn't even appear, but stays black and the couple of similar posts I found do not show a solution for this issue, but for the issue already mentioned where the screen is black from the beginning. It is not a matter of brightness, since the monitor is actually off.
I tend to agree that is an issue of graphic card, but I still don't understand why the screen in high resolution starts, then it blacks out after a few seconds. Also I don't understand why it was working for a few days, then it stopped.