I have encountered a bizarre black screen problem plausibly connected to kde. Given below is my rig, the symptoms, and my analysis. I invite analysis/comments/suggestions.


1. my rig

cpu : Intel I5-4440 Processor BX80646I54440
mobo : (64 bit) Gigabyte H97 SATA Express M.2 SSD UEFI DualBIOS DDR3 1600 LGA
memory : 16 gb
psu : corsair cx series 600 watt
hdisk: (old) maxtor diamondmax plus 9 80 gb sata/150

no video card; no video drivers consciously installed. I totally rely on the mobo's onboard video.
no anti-virus software installed.

os : 64 bit fedora 22, converted from gnome desktop to kde4
currently, from konsole : help : about konsole - KDE Frameworks 5.17.0, Qt 5.5.1


2. symptoms

Cold boot triggers completely black screen without even a visible cursor, _before_ any bios messages (e.g. DEL ..., F12 ...) or Fedora 22 version number appears on the screen. Other than root, I have one user-id, steve. Black screen also prevents user login of steve from displaying. I wait 5 minutes after starting the cold boot, presume that login is ready, and then (blindly) hit the _enter_ key to log in to the fedora - kde desktop, under the steve user-id.

The login is normally confirmed 2-4 minutes later by an audio "software update availability" notification, with the screen continuing to remain black. This notification does NOT occur prior to "entering" the fedora - kde desktop. Then, about 50 minutes later the black screen is replaced by the (visible) fedora - kde desktop.

On home built pc, I installed fedora 22 and (almost immediately) converted from gnome to kde sometime around June. About 4-8 weeks later, with no hardware changes, and software changes occuring via the (internet) software updates, the black screen began, with a lag time (following the login) of about 5-10 minutes. I have installed wine, libreoffice and (usenet - sabnzbd).

Since the black screen first surfaced, the lag time has been steadily increasing, and is now 50 minutes. HOWEVER, from within the fedora - kde desktop, if I completely power off (shutdown), and then do a COLD BOOT ABOUT 30 SECONDS AFTER THE SHUTDOWN completes, THE BLACK SCREEN IS BYPASSED! In this scenario, the bios messages and fedora 22 version number are displayed, followed by the (visible) login screen. Continuing this scenario, after login, the fedora wallpaper appears normally, with (visible) loading of the kde desktop (no black screen after login).


3. my analysis

I initially assumed that kde was NOT the problem, since the bios messages (e.g. DEL ..., F12 ...) are being intercepted. This suggests that the hard disk's boot sector is "going bad", or some malaware is slowly strangling the cold boot process. Unknown whether this suggestion is viable, given behavior of cold boot 30 seconds after shutdown, re previous paragraph. Analysis from hardware guru needed here.

Re above paragraph, there may be 1 problem or 2 problems. Possible that steady increase of lag time is somehow due to ongoing software updates, or increasing data in either /home/steve/.cache/ or /home/steve/.kde/. As Linux newbie, I'm out of my depth googling "kde black screen".

If kde bug involved, it seems imprudent to wait for kde.org to rectify.

Before even the BIOS shows up, the video bios should print on screen - if that doesn't happen either the HW is broken or there's a failure in establishing the output. Since VGA and DVI are pretty much robust, I'll take the wild guess that the monitor is wired by hdmi?

In that case even just re-plugging may "fix" it, switching the cable *may* resolve it.

I doubt this will be an issue with KDE - the intel kernel module may possibly be able to break the HW, but that should not depend on the cold/warm boot.

thanks for the analysis, luebking. the hardware can not be broken, since (each time), the black screen is eventually overcome. Unclear what "video bios" refers to; however, (each time) if I turn on the monitor (only), it registers "no signal received" on screen, indicating that the pc has not been turned on yet.

I believe that the hardware is NOT broken, and that "something" (presumably software) is intercepting the bios messages on the standard cold boot, but NOT on a COLD boot initiated 30 seconds after a TOTAL shutdown.

Absolutely no software can interfer before you'd see the grub boot screen.
The very first thing is that the graphics card posts some message (it's the initial content of the scanout buffer and you should briefly see that before the system BIOS posts it's stuff. UEFI could be broken enough here, but still no software invoked.

Is it a HDMI connection?

monitor capable of hdmi, i suspect, but connection definitely standard, rather than hdmi. Prior to problem (when pc first built), the bios message (DEL... F12...) would appear at the bottom of the screen SIMULTANEOUS with listing of various fedora 22 operating systems for me to choose to boot from. I always choose the (default) fedora 22 listing, at the top of the screen. Since the bios message and fedora 22 messages are displayed simultaneously, subtle bug in the boot sector has a "chance to kick in", rendering the screen totally black. Thus, at least with my mobo-bios, boot sector flaw could be generating black screen.

This all begs the question: what hypothesis explains NO BLACK SCREEN on COLD BOOT initiated 30 seconds after TOTAL shutdown?

Remaining voltage, temperature, voodoo. Thingd that work depending on when the system was bootoed usually point HW issues.
Let's assume that not the case and you miss the video BIOS and pre-grub (sure you're not selecting from UEFI?) because it's too brief, grub could have been configured for a framebuffer resolution beyond the HW caps.

https://wiki.archlinux.org/index.php/GR ... resolution

Maybe start by disabling the framebuffer in this stage:
https://wiki.archlinux.org/index.php/GR ... ramebuffer

Thanks to luebking for the ongoing debate. I checked the bios settings: the following relate to UEFI, whatever this is:

boot mode selection : UEFI and legacy
storage boot option control : Legacy only
other PCI device rom priority: UEFI oprom

There have been no hardware or bios changes following conversion from gnome to kde. Following this conversion, there was a 4-8 week period of no black screen. The black screen starts doing the boot process and extends into the desktop. The question remains: what is causing the black screen during a cold boot, but not on a cold boot initiated 30 seconds after TOTAL shutdown?

As newbie, I'm very uncomfortable exploring luebking's latest suggestions, especially since there has been no (deliberate) hardware change. Again, hard to believe that ongoing hardware or malaware-triggered deterioration is causing this. I agree that it is bizarre to attribute this to kde, but so many other kde black screen problems have been reported.

The "black screen issues" usually refer to either crashing plasmashell (ie. no desktop, but the screen is actually operative) or kscreen turning off all screens (happens with session login)

Things that affect the system from even before the boot process are due to bugs in the bootloader (UEFI), conditionally in a grub plugin to UEFI - or in the hardware.
Given the "works if the system was just powered" state: it's the hardware.
The most typical cause for this behavior are failing handshakes in either HDMI or DisplayPort, DVI and VGA should be more robust itr - so if you can, try with such connection (and a DVI-to-HDMI adapter is *not* a DVI connection!)

Is the initial cold boot from a totally unpowered system (or just "soft-off", ie. the board is still connected to AC/DC?) - if so, seek to power it some seconds before pushing the start button.
You can try to turn on the monitor "ahead" (ie. switch it on, wait 1 or two seconds, the turn on the computer) and likely pressing ctrl+alt+del in the early phase (before the system boot!) of the first cold boot might "resolve" this.

Leaving that aside, there still is a chance that for whatever trigger, the IGPs nvrm is left in a "bad state" (ie. a bug between kernel module and hardware), but that somehow doesn't explain the "only on really cold boot" condition.

Resolved - hardware - monitor was (progressively) going bad. Replacing the monitor totally resolved the problem. Thanks again to luebking for the analysis.