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I have an Asus VK221D 22" monitor. I don't recall seeing these horizontal wavy lines when I first setup this monitor a few months ago, but it may have been there. Anyways I see these horizontal wavy lines from the left to the right of the screen. It's not very noticeable unless you have a solid color background.

I have checked the cables they seem to work just fine, I have tested it with other cables and it doesn't change. I've heard of power electrical issues being the culprit, but does anyone know how I can test this theory?

What about video card settings I have a Nvidia 9800 GT.

Many thanks to all who respond!

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Are you using a VGA or DVI cable to connect the monitor to the video card? Are you using the monitor's "native resolution"? – Suppressingfire Nov 13 '09 at 4:35
VGA and yes NATIVE 1680x1050 – AskaGamer Nov 13 '09 at 4:36
I assume you've press the resync (aka auto-adjust) button on the monitor a few times? – Suppressingfire Nov 13 '09 at 4:39
Yes, that has been done. It's not a simple fix or else I would have found it. I figure it has to do with the power or some video setting. If its neither of those than it must be hardware related and in that case ASUS will repair it for free but I have to ship it there and be without it for 7-10 days plus ship time – AskaGamer Nov 13 '09 at 4:41
up vote 2 down vote accepted

Never buy LCD displays without digital interfaces! I never understand why even today VGA only models show up. DVI should be the minimum supported interface. Good luck your 9800GT has VGA too, I would not equip a card like that with VGA (guess you got a converter plug with it). But with VGA, the only thing to do is to minimize interference.

  • Use all grounded plugs and sockets
  • Use the shortes VGA cable possible, preferably with a magnet around the cable at one end. No loops in it.
  • Use 60Hz as refresh rate, and nothing else.
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Thanks bert, I know I made a mistake when I purchased this Asus monitor. I should have waited for a better deal on one that had DVI. Anyways, I will check on the ground and mess with the power. I am using a short vga cable with magnets. – AskaGamer Nov 13 '09 at 10:03

Do the lines gradually move from the top to the bottom of the screen (or vice-versa)? Sounds like it could be electrical Feedback. Try plugging your computer into a different wall socket from your monitor. If the lines disappear then electrical feedback is definitely the problem. If you don't have a second wall socket nearby, then using a digital connection from computer to monitor may help (Assuming your video card has HDMI or some other DVI output and your monitor has matching input). I've also heard that ferrite beads on the power cables can cut out feedback.

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This was my problem. Unfortunately my laptop's power outlet is right next to the VGA Out, maybe I can wrap some tinfoil around the wire... – brian Sep 29 '10 at 15:58

I have the Asus and I realized the power cord for my laptop was causing the issue, try unplugging the laptop and run on battery power, if this is the cause you will have to try using 3 to 2 plug converter or remove the ground from the plug. However still plug the computer into a surge protector for safe keepings.

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