Screen has black squares intermittently - "BadWindow" messages

[oygle]

For the last few weeks the screen/monitor on this Dell laptop has been intermittently having these black squares. They appear for a second or two then disappear. I initiall y thought it was the laptop screen on its way out, but looked at the file .xsession-errors

qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 12983, resource id: 54536997, major code: 18 (ChangeProperty), minor code: 0

Thousands of these messages, but I don't know how frequently that file is cleared ? Found a post at https://superuser.com/questions/1451...tion-xcb-error , but that is only how to suppress the messages.

Is this a bug ? Or how can I fix it please ?

[QIII]

Could you attach an image, please?

If you can't print screen at the time, snap a picture with a cell phone and paste it as an attachment.

[oygle]

Could you attach an image, please?

If you can't print screen at the time, snap a picture with a cell phone and paste it as an attachment.

To catch it will be very hard, as it goes within a second or two, disappears, then later it may appear again. It is very much like the picture at https://silicophilic.com/black-box-keeps-flashing/

It does seem to be more prevalent when there are quite a few Firefox windows/tabs open, and as I move from one to the other, the black boxes appear. Different sizes, different positions, so it may be resources ?? I did check the Nvidia driver, to make sure I was using the correct one, and it is.

Relating to that link, I did adjust the brightness a few weeks ago, as it was too dull. The contrasts is not great either, and I can get a deeper/better view when I hook up a large monitor. Although I haven't done that for quite a while.

Thanks for your help.

[Autodave]

I would hook up another monitor and see if it does it with that. You may also want to check your connections and try another cable.

[oygle]

I would hook up another monitor and see if it does it with that. You may also want to check your connections and try another cable.

Thanks for your reply. I did have another monitor hooked up, but of course it can only be hooked up as HDMI and it is a reflection/mirror of the laptop. So yes, it did happen on the external monitor, because the source was the laptop. The laptop screen/monitor is directly connected, internally, there are no external cables (other than when I hook up via HDMI)

[Autodave]

Can you give us make and model of the laptop please? Also, where did you get the nVidia driver from? What driver is installed?

[oygle]

Can you give us make and model of the laptop please? Also, where did you get the nVidia driver from? What driver is installed?

It's a Dell Inspiron 3542 - Specs are at https://downloads.dell.com/manuals/a...uide_en-us.pdf

$ ubuntu-drivers devices

WARNING:root:_pkg_get_support nvidia-driver-390: package has invalid Support Legacyheader, cannot determine support level
== /sys/devices/pci0000:00/0000:00:1c.4/0000:08:00.0 ==
modalias : pci:v000010DEd00001341sv00001028sd00000653bc03sc02 i00
vendor : NVIDIA Corporation
model : GM108M [GeForce 840M]
driver : nvidia-driver-390 - distro non-free
driver : nvidia-driver-418-server - distro non-free
driver : nvidia-340 - distro non-free
driver : nvidia-driver-460 - distro non-free
driver : nvidia-driver-450-server - distro non-free
driver : nvidia-driver-470 - distro non-free recommended
driver : nvidia-driver-460-server - distro non-free
driver : xserver-xorg-video-nouveau - distro free builtin

When I look in Synaptic, there is a nvidia-driver-460 , plus other nvidia-*****-460 packages installed. There is also a X.Org X server -- Nouveau display driver installed, so I don't know if any conflicts ??

It's either the laptop screen on its way out, or resources. I say resources because although this is a quad code CPU and I think 8 Gb RAM, plus plenty of disk, it is VERY slow the last few months. Applications , try to open, the 'wheel' spins for up to 10 or 15 seconds, plus a number of apps just don't load. Have to keep trying until they do.

Oops, I just realised I should have 470 installed, as per the bash display

[oygle]

Have now installed nvidia-driver-470 and uninstalled nvidia-driver-460

[Autodave]

I hope that the 470 driver fixes it, but I doubt that it will. What happens if you boot the maching using a USB installation stick?

[oygle]

I hope that the 470 driver fixes it, but I doubt that it will. What happens if you boot the maching using a USB installation stick?

Yes, the 470 didn't fix it. What will booting from a usb stick prove or not prove, when the problem is intermittent, and there were hundreds of updates since the initial installation. It is only perhaps matching something now against something that was, so where will that lead to ?

I've just seen this post at https://ubuntuforums.org/showthread.php?t=2465060 , and looking through that forum and this one, many video problems. What's the solution ?