Screen black on log on

deretsigernu · 10-08-2016, 10:07 PM

When I start Slackware, the screen stays black. The start up/log on process runs normal, except for that. I have to hold down the button that makes the computer screen brighter in order to see the login screen. Is there something I can change to make the start up process have normal screen illumination when the computer starts? I don't have this problem with starting the Windows the partition.

frankbell · 10-08-2016, 10:42 PM

Quote:

When I start Slackware, the screen stays black.

I'm not trying to nitpick; I'm just seeking clarity. Do you mean you see no messages on the screen at all or that the screen maintains a black background with white text? I'm guessing the former, but I'd like to make sure. If it's the latter, do you see any hint of the normal boot-up messages (for example, very faint text) or none whatsoever?

Also, what is the make/model of the computer, what is the Slackware version, and what is the video chipset?

deretsigernu · 10-09-2016, 05:55 PM

Well, I should qualify. At first, it gives the start up messages, but then after about 5 seconds, it changes to completely black. The boot continues, but then there are none of the usual start-up messages visible and the log-in screen isn't visible until I hold down the increase screen brightness key. The computer is an HP ENVY 15. The Slackware version is 14.1. The video chip is Intel HD graphics 4600, "Video BIOS 2179".

enorbet · 10-09-2016, 06:57 PM

You probably need to use the "append =" line in lilo.conf (or in grub if you're using it) to either "nomodeset" or something like "640 x 480" to not start the framebuffer mode.

Jjanel · 10-10-2016, 01:47 AM

Quote:

the log-in screen isn't visible until I hold down the increase screen brightness key

So 'all' is ok/alive, the problem is specifically that ?something? *'turns' the brightness* all the way down, during booting?
(I'm not sure what effective web-search keywords to use for this, but other LQ'ers will likely help, once you clarify this.)

Update: Oh! linux boot turns brightness down to black
returns a lot, e.g. this; use its title for better keywords
(might be GUI/WM/DE/Xorg/X11 related, rather than 'distro'-specific!)
p.s. you might like onebuck's Slackware Links!

allend · 10-10-2016, 04:42 AM

Quote:

The computer is an HP ENVY 15.

I have come across this blog post that _may_ be relevant, but is not a perfect match with your hardware.
It suggests that the HP Envy 15 has had problems with buggy firmware, that may have been fixed in a BIOS update dated 2016-04-14.
Of particular interest was:

Quote:

Firmware bugs

1. Missing function for the default backlight, this function sets the default backlight level to 30, on this machine the max is 255 (/sys/class/backlight/amdgpu_bl0/max_brightness).

You could try booting using the 'acpi=off' kernel boot option, to test whether this is an ACPI related problem.