Member Avatar for majestic0110

Hi all, I hope you are well. I am very new to Ubuntu and I am experiencing occasional screen flickers (the monitor will go black for a split second, then resume as normal). Now, I have tried googling for a solution but I have not found one yet that satisfies the issue. As you can imagine, its rather headache inducing. My system is a Toshiba satellite pro p100 PSPAE notebook. I have an nVidia Geforce go 7600 and I have installed the Nvidia server setting utility and have driver 180.44. My distro is Ubuntu 9.04 (jaunty) GNOME 2.26.1.
Things I have tried to do to rectify the flicker include : DISABLING "Force full GPU scaling". I also tried specifying a refresh rate of 60mhz resolution = 1440*900. Although everytime I apply this, the X utility reverts my preference here back to AUTO (only with the refresh rate and resolution: it remembers the disabled "Force full GPU scaling". Sorry about the long post, I am just trying to provide as much information as possible. Thanks for your time and I hope we can sort this together as it is giving my eyes some trouble!!

  • 4 Contributors
  • 4 Replies
  • 547 Views
  • 11 Months Discussion Span
  • Latest Post Latest Post by regularStranger

Dani AI

Generated

A short, practical triage and fixes list that complements the suggestions already in this thread.

Start by isolating driver vs hardware. Switch to a text console (Ctrl+Alt+F1) while you wait for a flicker: if the console also blacks out the problem is almost certainly hardware/firmware; if it only happens in X it is almost certainly the X driver or compositing. Check X for clues by scanning the X log for errors and warnings; this often points to mode, EDID or driver problems. (wiki.ubuntu.com)

Quick, safe tests you can try without reinstalling drivers:

# look for X errors/warnings
egrep '(EE)|(WW)' /var/log/Xorg.0.log | tail -n 50

# temporarily disable X power-management/screen blanking
xset s off -dpms

DPMS/screen-blanking can cause very short blackouts when the display or driver mis-negotiates wake; disabling it is a fast way to rule that out. (wiki.archlinux.org)

Driver-level knobs that often help (safe to test, revert easily): turn off OpenGL "flipping" (the NVIDIA setting labelled Allow Flipping / NoFlip) and try disabling aggressive GPU power management (PowerMizer) while you test. Example xorg.conf snippet to force flipping off:

Section "Device"
  Identifier "Device0"
  Driver "nvidia"
  Option "NoFlip" "True"
EndSection

These options are provided by the NVIDIA driver and are commonly effective at removing intermittent redraw/flicker symptoms. (download.nvidia.com)

If those steps do not stop the flicker, try a different driver to isolate regressions: use Ubuntu's Additional Drivers tool or temporarily switch to the open-source nouveau driver / a live Linux image. Driver regressions can and do introduce flicker; switching versions is a useful diagnostic. If flicker persists with a live system or nouveau, inspect for hardware faults (LVDS/flex cable, hinge, panel) — worn hinge/cable faults are a classic cause of intermittent blackouts on older laptops. (help.ubuntu.com)

Notes tied to thread posts: ’s refresh-rate/save-to-xorg approach is exactly the right first move for EDID/mode issues; ’s glxinfo loop is a symptom-masking workaround that can confirm a GL/driver sleep problem but does not replace the driver/DPMS/NoFlip checks above; ’s reminder to verify monitor specs is also correct and often relevant. If nothing helps after these steps, collect /var/log/Xorg.0.log, dmesg, and a short video of the flicker — those make a much stronger bug report or service case.

Recommended Answers

All 4 Replies

Member Avatar for cent25

I have a notebook with the same video card as you, and installed the nvidia GLX drivers some time ago. I had not noticed this occasional flicker until today, and am unsure what would have changed to cause it.

Edited by cent25 because: n/a
Member Avatar for majestic0110

Hi there Cent25, I have found a fix for this (at least on my machine). Press alt-F2, then when the Run Application window appears type :

gksudo nvidia-settings

This will run the Nvidia server X utility as root. Now, my monitor supports a refresh rate of 60hz, so I imagine yours does too. Go to X Server Display Configuration and set the refresh rate to 60Hz (even if it says auto, change it). Now apply this, save to x configuration file then restart and you should be ok! I really hope this helps, I know how irritating this flicker is.

Member Avatar for blud

On that note, I would recommend looking up your monitor specifications, because some support an even higher refresh rate, and over time, that is a setting that becomes very obvious.

Member Avatar for regularStranger

So I've had this flicker problem through several Ubuntu versions, and I suspect it's more likely a problem on the Nvidea side, and I'm annoyed that it hasn't been fixed yet. My hack fix involves installing mesa-utils (sudo apt-get install mesa-utils) and then save the file...

#
glxinfo > /dev/null;
sleep 10;
./glxhack;

Save the file somewhere, make it executable, and run it. Set it to run on startup. Something about the glx system (or something - I'm kind of making up stuff) goes to sleep after a certain amount of time, and when it reawakens it causes a flicker on screen. Running glxinfo repeatedly prevents it from going to sleep. I hope this solves your problem. It has always solved mine.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.