I have an Acer G195HQL LCD monitor and recently I've been noticing a lot of disturbance on the screen. They appear to be like flickering horizontal white lines. These lines are more apparent on dark backgrounds like grey/black. The curious thing is that, the intensity of these lines increases and decreases with no specific pattern. The disturbance temporarily goes away when I detach and re-attach the VGA cable at the CPU end. My speakers are magnetically shielded, but the problem persists even when I turn them off. I don't know what to do and this is really annoying me. Is it possible that my monitor is failing? Or is there anything I should check?

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    You haven't modified your screen refresh late, or any program has, have you? – cutrightjm Apr 12 '12 at 16:49
  • @ekaj Nope. Mine won't go over 60HZ – Uday Kanth Apr 12 '12 at 18:16

Try another cable (and check for loose connection at the monitor's end), and try the monitor on another machine. If it shows the same problems there, the monitor is most likely defective.

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    The connection's pretty firm at the monitor's end. But it's a bit loose at the CPU end and there seems to be nothing I can do about it. Anyway I guess I'll buy a new cable and see, since most people are advising me to do the same! – Uday Kanth Apr 12 '12 at 18:20
  • @UdayKanth If it's a standard VGA cable it should have screws (normally thumb screws) built into the plug ends to secure it. – Dan Neely Apr 12 '12 at 19:15

The self test is a good way to check that. It can sometimes be difficult to see if the colors are warped, but it's a good test. Just unplug the monitor from everything, leaving the power cable plugged in and you should get the multicolor self test. Leave it up for a while to see if it does the same thing.

Trying another cable (Like Renan suggested) is an excellent idea, and it sounds like it could either be a cable or a video card issue rather than the monitor.

  • Looks like my monitor does not have a self test feature! It's displaying a 'Cable not connected' message. But you said it could also be a video card issue. What could have triggered this? A driver update? – Uday Kanth Apr 12 '12 at 18:31
  • Possibly. Also check the level that it's running, whether 60 hz or 75, that can cause problems like this too. Driver updates can cause it, overheating, card is loose, connector screws are loose. If you have another add-in card, you could try that, even if it's an el cheapo. – Ryker Apr 12 '12 at 23:57

the problem is nor clearly defined here but i think i had the same with my 23" aoc led monitor (e2343Fs). on dark background, colorful or white areas start to extend with faint lines sometimes so long that a shadow of these areas start to form to the right. (lines extend to the right in my case, not either way)

trying every resolution, contrast and brightness options didn't work, so i bought a new vga cable, just to make sure the monitor is defected. and it worked!!! now i have the expected clear image on the monitor.

hope it helps...


First off I know I am responding to an old post but people are still finding answers here. If your PC or docking station has either a display port or HDMI outputs use these instead of VGA. VGA cabling is a very old standard and modern graphics push its limits. Display port and HDMI were created to overcome these limitations. The best advice I can offer is to use any cable other than VGA.

how to ID video ports: http://support.benq.us/customer/portal/articles/2036687-how-do-i-connect-my-monitor-to-my-computer-

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