When TechRepublic first published steps to keep your monitor free from flickers it was 2001, and the computer world was vastly different. Cathode ray tube (CRT) monitors were the norm, and as anyone who has supported a CRT will tell you, they’re far more sensitive than modern LED screens.

That doesn’t mean flickering can’t still happen to a flat screen monitor: Many of the causes of screen flickers are the same in 2018. Some issues, like electromagnetic interference, are things of the past, but these five tips for fixing screen flickers are largely the same as they were almost 20 years ago.

1. Check your cables

It doesn’t matter if you’re using a VGA, HDMI, DVI, or displayport cable to connect your monitor to a computer: If the cable isn’t securely connected there are going to be issues.

Check the cable at both the computer and monitor ends. If tightening it down or reconnecting it doesn’t fix the problem try replacing the cable with a new one. If that doesn’t fix the issue it’s time to investigate something else.

2. Check the monitor refresh rate

Monitor refresh rate is the number of times the screen image is refreshed in a second, as measured in Hertz. If the refresh rate isn’t optimal, or is too low, flickering, lag, and other issues can occur.

You can check the refresh rate on a Windows 10 PC by hitting the Windows key, typing “refresh rate” into the search field, and then clicking on View Advanced Display Info. From there click on Display Adapter Properties For Display 1 (or whichever number display is causing the issue).

Click the middle tab, titled Monitor, in the properties window that appears and you’ll see an area to set the refresh rate.

If you’re unsure what it should be set to, consult your monitor manufacturer’s website and you should find info on the optimal refresh rate for your model.

3. Check the video card

A video card that isn’t properly seated on the motherboard can cause a lot of problems, including a screen flicker. Turn the computer off and open the case. Find the video card and check to see if it’s properly connected.

If the card is seated on the motherboard properly but the issue persists, a faulty card is likely the issue. Testing this is easy, especially if the problem computer has an onboard GPU that you can plug into.

Power down the computer, remove the video card, and connect the monitor cable to the onboard card or a second video card you’ve replaced the old one with. If the problem persists then the issue isn’t the card–it’s something else.

4. Test the monitor

It’s always possible the monitor itself has gone bad, but before you consign it to the recycling pile there are a few things you should do.

Inspect the monitor for physical damage as well as using the monitor’s onboard buttons to check for settings that may be causing the issue.

SEE: Hardware decommissioning policy (Tech Pro Research)

If everything looks okay it could still be a bad monitor–unplug it and replace it with another one. If the new monitor is working properly you’ve found your culprit.

5. Is there really an issue?

In the original 2001 article, TechRepublic’s Bill Detwiler said something every IT professional can likely attest to having seen before: It may not be a problem and the user might just want a new monitor.

“It is possible that the complaining end user simply wants a newer or larger monitor and thinks complaining about his or her existing screen will accomplish this,” Detwiler said, adding that there’s a way you can make the user happy and not blow budget money on a new monitor at the same time.

“I recommend giving the offending user a different monitor that you’ve been using as a spare. Clean it up and tell the user it’s a newer model than the one they have. If you’re lucky you can even find one that’s a bit bigger than the one they had. Everyone’s happy, and it doesn’t cost a dime.”