Horizontal waves on monitor

I am getting very light horizontal waves on my 19 inch Acer monitor screen. At first I thought they were coming from videos I was watching, but they also occur on other displays. I checked the connectors on my VGA cable, then changed to a new cable. Sometimes they move up, sometimes down, sometimes they disappear. At this moment they have stopped.

My VGA information.

 01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS780L [Radeon 3000] (prog-if 00 [VGA controller])
        Subsystem: Biostar Microtech Int'l Corp Device 0017
        Flags: bus master, fast devsel, latency 0, IRQ 18, NUMA node 0
        Memory at d0000000 (32-bit, prefetchable) [size=256]
        I/O ports at d000 [size=256]
        Memory at febf0000 (32-bit, non-prefetchable) [size=64]
        Memory at fea00000 (32-bit, non-prefetchable) [size=1]
        [virtual] Expansion ROM at 000c0000 [disabled] [size=128]
        Capabilities: <access denied>
        Kernel driver in use: radeon

Where do I start to diagnose the problem? Whoops! They just started again.[/size][/size][/size][/size][/size]

It could be due to a shielding issue with the VGA cable, and from experience quality does matter. Many modern VGA cables are not of high quality. Most of us are now using digital interfaces (HDMI and DisplayPort). I really don’t miss analog video signalling.

Is your Acer an old CRT screen? Does your Radeon provide any digital outputs that match your Acer?

I don’t think developers pay much attention to analog (VGA) video any more. Digital quality is much better, and has been around for more than two decades now. As Deano suggested, cable quality matters, but there could be a software problem too. From Konsole or other GUI terminal, please provide output from

**inxi -SGa**
	or
**inxi -SGxxx**

As requested…

$ inxi -SGa
System:    Host: office Kernel: 5.3.18-59.19-default x86_64 bits: 64 compiler: gcc v: 7.5.0 
           parameters: BOOT_IMAGE=/boot/vmlinuz-5.3.18-59.19-default 
           root=UUID=078fae3b-4016-4b60-97b7-4abb3439b40f splash=silent 
           resume=/dev/disk/by-uuid/4d95efd5-12ea-46ed-9cac-41bf44340045 quiet 
           mitigations=auto 
           Desktop: Xfce 4.16.0 tk: Gtk 3.24.20 info: xfce4-panel wm: xfwm4 
           dm: LightDM 1.30.0 Distro: openSUSE Leap 15.3 
Graphics:  Device-1: AMD RS780L [Radeon 3000] vendor: Biostar Microtech Intl Corp 
           driver: radeon v: kernel bus ID: 01:05.0 chip ID: 1002:9616 
           Display: x11 server: X.org 1.20.3 driver: ati,radeon 
           unloaded: fbdev,modesetting,vesa resolution: <xdpyinfo missing> 
           OpenGL: renderer: AMD RS780 (DRM 2.50.0 / 5.3.18-59.19-default LLVM 11.0.1) 
           v: 3.3 Mesa 20.2.4 compat-v: 3.0 direct render: Yes 

…and thanks for helping.

Yes, I’m inclined to agree. Newer cables are thinner than they were 20 years ago, and metal shielding costs money. Unfortunately all my three monitors are 4:3 ratio and VGA and replacing them with HDMI models is beyond my budget at this time.

Please install xdpyinfo and run

sudo inxi -U

or upgrade inxi to the TW version, then post output from:

inxi -Ga

Please also post output from:

cat /var/log/Xorg.0.log | susepaste

If a file not found message results, instead paste output from:

cat ~/.local/share/xorg/Xorg.0.log | susepaste

all my three monitors are 4:3 ratio and VGA and replacing them with HDMI models is beyond my budget at this time.
Sorry to hear that. Do Sweden and Mexico not have thrift stores like we have in USA? Flat panel monitors with digital inputs routinely show up in them around here for chump change, far less than a motor fuel fillup.

  • DVI-D. Better than HDMI 1.4.

ILL you’re using VGA connector soldered on Biostar mobo.
Avoid doing that. Use discrete ATI/AMD video card, better with Terascale 2 or 3 chip (Radeon HD 5000 or 6000 series).
Do not use Nvidia and builtin graphics for VGA output.
Of course, using digital connection is preferable.

Set horizontal frequency for monitor. With VGA input press “Auto adjust” button on monitor.

$ inxi -GaGraphics:  Device-1: AMD RS780L [Radeon 3000] vendor: Biostar Microtech Intl Corp 
           driver: radeon v: kernel bus-ID: 01:05.0 chip-ID: 1002:9616 class-ID: 0300 
           Display: x11 server: X.Org 1.20.3 compositor: xfwm4 v: 4.16.1 driver: 
           loaded: ati,radeon unloaded: fbdev,modesetting,vesa display-ID: :0.0 screens: 1 
           Screen-1: 0 s-res: 1280x1024 s-dpi: 96 s-size: 338x270mm (13.3x10.6") 
           s-diag: 433mm (17") 
           Monitor-1: VGA-0 res: 1280x1024 hz: 60 dpi: 96 size: 338x270mm (13.3x10.6") 
           diag: 433mm (17") 
           OpenGL: renderer: AMD RS780 (DRM 2.50.0 / 5.3.18-59.19-default LLVM 11.0.1) 
           v: 3.3 Mesa 20.2.4 compat-v: 3.0 direct render: Yes 

$ cat /var/log/Xorg.0.log | susepaste
Pasted as:
   https://susepaste.org/18270334
   https://paste.opensuse.org/18270334
Link is also in your clipboard.

I live in a small town. I am sure that I could find a thrift shop in Mexico City if I had a car, but that’s 270km. away and one of the most confusing cities in the world. As for Sweden, there are thrift shops in my home town but none seem to sell computer parts. In any case I’m banned from Sweden at present (Covid) and there would be the problem of bringing monitors back to Mexico. There is a Mexican online thrift page, but I have been burned buying different products. I can live with the problem, and I will try to but an HDMI monitor for at least the box that I use the most.

Try this from a GUI terminal or Alt-F2:

xrandr --output VGA-0 --mode 1280x1024 --rate 75

The data suggests you’re running @60Hz refresh on a display that supports 75. CRTs generally run best at the highest supported refresh. If this helps it can be put into a startup script to run automatically, if XFCE doesn’t have a setting where you can set monitor refresh to 75.

Some VGA cables only have 14 connectors instead of the 15 possible. Sometimes a change to a 15 pin cable helps.

IMHO OP has LCD monitor, not CRT.
With your suggestions he can damage monitor.

On what basis? In post #5 he suggests his screens are 20 years old, 4:3 ratio, and lack digital outputs. His log says the display is using 1280x1024 resolution, which is a 5:4 mode. These things smell like CRT to me. In contrast, his log says his Acer was made in 2009, but it also says 75Hz is supported for 1280x1024 (and 1024x768, and 1152x864), while it reports display size of 34mm by 27mm, which matches a 17" 5:4 1280x1024 LCD closer than anything else. I’m now of the opinion that this Acer is more likely suffering from one or more failed/failing electrolytic capacitors, rather than a software issue. Acer is known for using cheap caps in its displays.

1280*1024 17" or 19" VGA is typical for old LCD monitors.
For CRT I expect 4:3, not 5:4 ratio.
ILL Acer V173, 17", TN, supports 1280x1024@75Hz.
User may upgrade it to use DVI-D by changing some parts.

Of course, we need clear info from OP. Discussing monitor faults without exact model is a guess game.

Your suggestion turned out to be the simplest solution. Switched to 75 hz. and the waves have gone. Many thanks for the accurate diagnosis.