Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I've recently got an LCD monitor and it is occasionally 'flickering' colors very noticeably. It's not a new monitor, but the person I'm borrowing it from hasn't had any trouble with it.

The flickering occurs across operating systems and screen resolutions.

I'm pretty sure it's related to dirty power - it often happens when fluorescent lights get turned on or the fridge starts, but not always.

Is this likely to be the cause of the problem?

Is there any good way to test this?

Is there anything that can be done about bad grounding?

share|improve this question
up vote 0 down vote accepted

Could be a few things...

  • Artifacts - this is a GPU problem
  • failing backlight
  • faulty cables

If possible, go through the options with trial and error. If you have a new computer, you can eliminate the first possibility by trying the monitor on a different workstation or even laptop if supported. If you have a second computer, try using it's cables to eliminate the third option. You also mentioned the possibility of power problem - do other devices using this outlet show power problems from time to time?

Try diagnosing it step by step by yourself first, take it in for repair as a last resort.

share|improve this answer
My previous monitor with the same setup was fine - does this rule out artifacts? – stickmangumby Sep 25 '09 at 1:51
Adding to your "faulty cables" suggestion, it could also be a cable that isn't plugged in firmly. Try removing the cable, reattaching it, and screwing it down tightly. – CarlF Oct 8 '09 at 5:30
@CarlF This sounds very possible, especially if stickmangumby is using VGA. – prestomation Jan 4 '10 at 19:22
This is a problem for some laptops because they typically don't have a place to screw in the VGA cable, you just have to hope that it stays in! – omouse Sep 24 '11 at 5:56

You could try to put a power conditioner between it and the power source (or a good quality UPS). You could also try adjusting the refresh rate.

share|improve this answer
Refresh rate isn't usually an issue with LCD panels though. They usually only have one rate (60Hz). – ChrisF Dec 5 '09 at 13:05
Hmmm... I've got 4 different refresh rates available on my LCD monitor. – joeqwerty Dec 5 '09 at 22:11
@joequerty - I did say "usually" ;) Newer ones do have higher rates available, probably 75Hz and 85Hz. – ChrisF Jan 4 '10 at 19:02
@ChrisF: Gotcha. I was just mentioning my monitor specs as I thought it might be helpful. – joeqwerty Jan 6 '10 at 1:51

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.