Flickering monitor

pts.
Tags:
Help Desk
Tech support
One of our users has reported that his monitor is flickering constantly and is causing him some problems, eg headaches, sore eyes. I have had a look and there is a slight flicker. Here are the things I have tried so far that haven't helped. I tried changing the refresh rate to see if that would help, but the flickering was still there. Installed the latest monitor driver. Moved the monitor away from the wall where all the cables are located. Replaced the monitor with a brand new one. Replaced the monitor with a used, but working one. Replaced the PC with one that I know works without any problems. The user sits in his own office and there are no other computers near him. Any suggestions and ideas would be very welcome. Thanks Andrew

Answer Wiki

Thanks. We'll let you know when a new response is added.

Have you checked into replacing the video card? Maybe that is the bad part. Could you also not have the latest video card driver but instead be using a generic vga one?

Discuss This Question: 43  Replies

 
There was an error processing your information. Please try again later.
Thanks. We'll let you know when a new response is added.
Send me notifications when members answer or reply to this question.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
  • Pkuczyns
    You replaced the monitor, and the pc, and it's still flickering??? Pete
    0 pointsBadges:
    report
  • DrillO
    It is hard to know where to start. You have already checked the obvious and it clearly is not a hardware/software problem. Now, we have to assume that it is environmental. This isn't going to be easy. Things you have to look at....have there been any renovations in the building lately? You might have an electrician come and look at the power supplied to that office....often a line conditioner canmake a difference. Is there currently any construction going on in or near this building? Do you know if the local utility has been working in the area or made any major changes? Is anyone in the area, inner or outer, runing any heavy equipment or large electrical motors. I would almost bet that you are dealing with EMI (electro-magnetic interferance). This is going to be hard to trace, but in the interest of the health of the user, you really need to do your best to track it down. Good luck and let us know how you make out. Paul
    15 pointsBadges:
    report
  • Harg7769
    I have replaced both the monitor and the PC and there is still a flicker, that is correct. Could it have anything to do with the power supply as I have tried his monitor and his PC in another part of the building and there was no problem.
    0 pointsBadges:
    report
  • Tondarb
    Hi, Check the Graphic card, if it is Ok then check the PCI slot.
    0 pointsBadges:
    report
  • DigitalCreature
    Could it be EMI from nearby devices like mobile phone, radio speakers, etc. Try moving all the devices away from the monitor then observe the flickering. Is your using running all his computer, devices and appliance from one power outlet? If you replaced the computer and the monitor and it's still doing this, it must be something to do with radiation from nearby devices / fluorescent light, or the power outlet.
    0 pointsBadges:
    report
  • Michont
    Thought a bit more on this and was thinking maybe you might have a power issue. Try plugging the monitor into another outlet not near where you are getting the flickering issue.
    25 pointsBadges:
    report
  • Harg7769
    Thanks Paul, I'll have a look at your suggestions and get back to everyone if/when I find a solution.
    0 pointsBadges:
    report
  • Nerdking
    If all the hardware and software associated with the monitor checks out good look for sources of electromagnetic and mechanical interference. Bad lightng fixtures (florescencet lighting fixtures can appear to be good, but the ballast may be ready to go and you won't know until you try to turn on the light and nothing's there), radios, space heaters, fans, etc., whether they are plugged into the same circuit as the monitor or are just sitting in close proximity to the monitor can cause it to flicker. Has there been any work by the power or phone company in the surrounding neighborhood? Running machinery (furnaces, refrigerators, large multifunction printers/copiers, etc.) can set up vibrations that you may not hear or feel, but is at the right frequency to cause enough interference to make the monitor flicker. Again, these sources don't necessarily have to be in close proximity to the monitor but can be far removed -- even on another floor. We once had a similar problem. Turned out that a new pop machine in our 5th floor break room was the cause of a monitor flickering on a PC on the 4th floor. Didn't affect any other computers except this one. We moved the pop machine to another spot in the break room and the flicker was gone. If you can, try an LCD flat-panel and see if the flicker goes away. They have fewer components affected by these kinds of outside interference than a CRT does.
    0 pointsBadges:
    report
  • Nerdking
    Just re-reading the new posts after typing my message and it looks a lot of others have been thinking along the same lines of environmental causes as well.
    0 pointsBadges:
    report
  • Kcampbell28
    I would suggest having an electrician check the power outlet for a consistent 110/120V. Do you have a small UPS under the desk? If not, put one in and see if that helps. He might not be the only one having the problem; he might be the only one complaining about it?
    0 pointsBadges:
    report
  • Howard2nd
    You swapped the monitor, you swapped the PC, you tried the original units in a different location and had no flicker. You have done everyting right in troubleshooting the problem. It is enviromental! Something is generating an interfering magnetic field. Every AC motor generates a revolving magnetic field around itself when running. This field can extend a surprising distance depending on shielding. I can detect field disturbances from the elevator motors over 200 feet away. You changed the refresh rate to eliminate resonance with the flourescent fixtures - good thinking. A - does the user have a fan on or under their desk? (also small heaters have fans) B - is there any large electroninc equipment in the room? C - (my personal bet) Is the monitor on an outside wall or is the wall shared with another office? Is that office in your company or someone else? We had a similar problem when one group got a new copy/scan/fax system and put it on the wall shared with the director's office. Also look for underdesk refrigerators and dehumidfiers. Good luck
    30 pointsBadges:
    report
  • Macgvr
    I'm going to mention something really off the wall. Is the desk stable. It isn't vibrating or shuddering is it? I know it is a strange thought but I've seen stranger. The other thing with the flourescent lights is also a real possiblity.
    0 pointsBadges:
    report
  • Harg7769
    Thanks for all your suggestions guys. The monitor is near a separating wall and on the other side of it is the photocopier/ fax machine, so I'll see what happens if we switch the photocopier off. There is no other machinery in his office. He has a phone and a PC. there may be a heater but it is on the opposite wall. No fan either (we're in Scotland, it doesn't get warm enough to justify a fan!) The main electrical board is about 30 feet away so that could be having an effect but it hasn't affected any of the other PCs that are closer than the problem one. I'll go though all of your suggestions and get back to you when I have an answer, but thansk again for all the suggestions.
    0 pointsBadges:
    report
  • HumbleNetAdmin
    Somone has mentioned this in a previous post. I thought it might be worth mentioning again since the source of the EMI may not be so easily removed. Try replacing the monitor with a LCD monitor and it will most likly resolve the issue.
    0 pointsBadges:
    report
  • Druuna
    Hi all - One of the simpler solutions is to change the monitor refresh rate to around 75 Hertz. The monitor picks up on the pulse from the florescent lights and some people are sensitive to the flicker in the monitor. The best place to see the flicker is on a white back ground (Open Word up full screen). Some people can not pick up the flicker at all. Best of luck!
    0 pointsBadges:
    report
  • Mintun
    I'm not sure if you stated this before, but have YOU seen the flicker, or is it just the user seeing the flicker? I would also look to the Flourescent lighting (since they flicker naturally)... If the user is the only one who sees the flicker, I'd look for some sort of issue between the keyboard and the chair. :)
    0 pointsBadges:
    report
  • Aftabn
    Try to change the direction of the monitor. I had a problem similar to this one and moving the monitor resolved it.
    0 pointsBadges:
    report
  • Tracert
    Try Placing the monitor on a good power conditioner. Don't get the device confused with a surge protector or filter. Sometimes a circuit can be a little of in frequency or there is some form of harmonic on the AC line which could be causing the problem. If you are unable to obtain a good power conditioner then try a decent UPS with good front end conditioning. A good UPS can be a little pricey as they usually run anywhere from $1,000 to 1,500 dollars Can.
    0 pointsBadges:
    report
  • Bmccracken
    I have had the same problem inone of our offices, and have had a electrician look at it. I resolved the issue out bu using magnets on the video cord from the PC to the monitor, and have not had a problem since.
    0 pointsBadges:
    report
  • Harg7769
    Yes, I have seen the flicker myself. I don't think it's as bad as he makes out but then I don't have to sit with it all day. I did change the refresh rate to 75Hz and I thought it did improve it to the extent that the flicker was negligible but he still insisted it was there, so I have to keep looking. Andrew
    0 pointsBadges:
    report
  • Tfreestone
    Is this monitor a CRT? If so, you could try swapping it out with an LCD if you have the resources to do so. I have had to do that in the past when there was EMI that I couldn't find or eliminate.
    0 pointsBadges:
    report
  • Superfreak
    I can tell you one thing, at my former job I carried a Nextel with me all the time, and whenever I leaned close to a monitor it would flicker and do all kinds of things. Plus their speakers would make noise. Does this person carry a mobile digital device?? Also, just for grins, have you taken the questionable monitor to an office without this problem? My guess is the other responders are right and there is some form of EMI going on. Unless of course the user is a robot in disguise and they are causing it! OK, just a little humor..
    0 pointsBadges:
    report
  • DrillO
    Hi Andrew.... You made a comment in your last post about the flicker diminishing but the user is still at you about it. Boy, do I know that one. It will take some time to resolve this if the user is really picky as they sound to be. The suggestions regarding "chokes" around the power cord are good ones. I would really see if you can borrow a line conditioner.....I would almost bet this could help a lot. Hang in there......and rest assured, I feel your pain. I work in a place that is wild with those types of issues and users that insist they see things that aren't there. Good luck Paul
    15 pointsBadges:
    report
  • 2stroke
    Hi Andrew, WOW!...lots of great responses to this question? I had the same exact situation. I finally plugged the monitor & PC in a different outlet on a separate circuit to eliminate the electrical. I then shut-off all electrical appliances in the users office and started turning them on individually one at a time until the culprit was exposed. Twas the lighting' bad, evil, ballast! Not sure if this was mentioned but...u swapped PC boxes...did you swap the power cords for the monitor and the PC as well? Don't keep us in suspense...let us know what the culprit was! Good luck
    0 pointsBadges:
    report
  • Bobkberg
    Wow! Most of the good responses were taken - now I've got to think. Try taking the user to another machine (with no complaints) and sit him down there and see if the problem persists. As one other poster mentioned, there may be a problem between the chair and screen. Flat panels are a good suggestion, as are looking at speakers, cell phones, etc. Does the person listen to music CD's at the desk? Internet radio, regular radio? I know that I see odd patterns on the screen when listening to music because my monitor is in a corner and there isn't much space to move the speakers out. Other people have mentioned upping the refresh rate to 75 Hz. How far up that scale have you gone? My monitor/video card will go to 85 Hz, some may go higher than that. This one test is REALLY out there, but will prove the presence or absence of external causes. See if you can find an RFI testing lab with a Faraday cage and put the user and his computer inside the Faraday cage and see if the problem goes away. Finally - without meaning to cast aspersions on your user, but such things HAVE happened... Is there the possibility that your user is setting you up for a workplace health/safety issue lawsuit? Bob
    1,070 pointsBadges:
    report
  • BlueKnight
    Man is this a busy thread... lots of great responses too. I have to agree with nerdking and others leaning toward EMI. Every time I've had to deal with this issue, it was because the user had some sort of fan or heater plugged into the same circuit their computer was on. It nice when you have 2 different circuits running through the office - one for computers and one for all other stuff. This could, as others have mentioned, be a fan in someone elses office/cubicle that happens to be on the same circuit. Ideally, you'd want a separate circuit for the computers, but if the building isn't built that way, it can get pricey having a separate circuit installed. After fans and other devices with motors, I'd look toward the flourescent lighting ballast. You might even put new tubes in the fixtures for grins to see if that helps. I don't know if switching the tube type would help or not, but there are some tubes that emit more of a "pinkish" light than white -- that may or may not make a difference. Since you've checked the PC and monitor indifferent areas without problem, I'd be inclined to look at PC parts as being the problem last. I would definitely try clamping suppression magnets around the power cords of both the PC and monitor. You should be able to find those at your local electronics store. It looks like you've covered all the bases, and comments from others cover virtually every area I would consider. Keep in mind also, that even though you may have what seems to be a solution, you might never totally satisfy the user simply because some people's eyes are sensitive to refresh rates of monitors and can detect flicker where most others cannot. Switching to an LCD monitor is a very good suggestion. Let us know what your final solution is when you find it. I'm curious and I'm sure others are too. Good luck, Jim
    10 pointsBadges:
    report
  • Stevesz
    I had the same kind of situation at a client's site a few years ago. I could not resolve the problem in any way. Finally I hit upon it. You might remember seeing those aluminum foil hats to ward off evil rays from interpanetary beings, or our own government? (Here is a site, if you are really curious, http://zapatopi.net/afdb.html. It states, in part, "An Aluminum Foil Deflector Beanie (AFDB) is a type of headwear that can shield your brain from most electromagnetic psychotronic mind control carriers."). Well, I fashioned, from cardboad and aluminum foil a "beanie" for the monitor. It worked. It blocked the radiation (probably from all the phone company and ISP equipment in the room on the other side of the wall, ouside the office suite), and made the monitor flicker free. On subsequent visits, the ladies had fancied up my creation, but I got no more complaint from them on the monitor flicker. Also, a reminder for everyone out there, take reports of monitor flicker seriously, even if you do not notice it yourself. Some people are very sensitive to it, while others seem to be practically immune. If you don't see it, make adjustments anyway, or get another set of eyes in there with you. Steve//
    2,015 pointsBadges:
    report
  • Joelsplace
    I had this exact problem that appeared suddenly one day on 2 outside walls of an office. The computers already had UPSs and I tried running a cord from another circuit with no luck. I moved a computer and monitor to the middle of the building and it worked fine. I even tried the make your own shield trick with no luck. I finally traced it to a transformer that had blown out a few blocks away. The utility company was rerouting power through the lines outside the office and it was messing with all the monitors that were within about 50 feet of the wires. The building across the street was having the same problem with their monitors on the side facing the power lines. I found a company that made a monitor shield for just such a problem but they decided to live with the flicker because the shields cost several hundred dollars each. One monitor that was affected constantly changed focus sharp-blurry-sharp on a couple of second interval. The user didn't mind but I couldn't look at it for more than a few minutes without getting a killer headache.
    0 pointsBadges:
    report
  • RobertK93
    A Flat Panel LCD Monitor is not subject to EMF like a CRT. This is your best bet.
    0 pointsBadges:
    report
  • Harg7769
    Morning all, Phew, quite a few suggestions here, thanks to everyone for taking the time to respond. I have swapped his CRT monitor with an LCD monitor for the moment to see how he gets on with that. It doesn't reallyt answer the question about the flickering admittedly, but if it keeps the user happy then I'll go with it just now. If he still complains, then I'll look over the suggestions again. Thanks again Andrew
    0 pointsBadges:
    report
  • DrillO
    I'm glad to hear that you have switched the monitor. By all means continue to lok for the source of the problem as you have time. I would guess that at this point, if the user still complains, Bob's suggestion about Health and Safety may make more sense. I have run across this in other areas and the people are usually successful in getting all sorts of things. Make sure you do your hmoework and get supporting paperwork on the LCDs and the lack of effect form EMI. Quite simply, LCDs don't flicker. I hope this all resolves for you with no further problem. Best, Paul
    15 pointsBadges:
    report
  • Joshuu
    I'm almost certain its insufficient power problem.Try to use another power outlet otherwise call an electrician to check those power outlets if they have a problem.Good luck
    0 pointsBadges:
    report
  • Farokh
    Wow! Look at all those responses. Ask a questions about VPNs and you get 4, maybe five responses. But a flickering monitor, now that is something to sink our teeth into. One of the most important things you mentioned is that the flickering goes away when you move the computer to another location. This means the problem is not related to drivers or monitor refresh rates, but rather to the environment. The first thing I would try is installing a TrippLite Isobar. I have been using these things for years and have found them to solve problems such as the one you have described. Isobars are not expensive and filter out a lot of dirt from electric lines. The only other advice I have is to look for motors (fans) and magnets (speakers) that would be nearby, as others have done already.
    0 pointsBadges:
    report
  • Jlnewmark
    Okay folks, I'm going to throw my hat into the ring: I DO have a flat-screen monitor and regardless of refresh rate (I've tried all available settings 60-85 mHz)or monitor driver, I get "ripples" across the screen. I have vision problems and this is migraine city in less than an hour. I'll be taking all the wonderful suggestions here that I can in the environment, and let you know if anything works. But why do people think that LCD monitors don't have these problems? Am I really THAT odd?
    0 pointsBadges:
    report
  • Bobkberg
    Hi jlnewmark, and welcome to both you and your hat. First of all, I don't think you're odd - or at least not for the reasons described... :-) Seriously, visible rippling is usually caused by frequencies in the audio range - this can be AC power (on the bass end for example), so look for sources of music, video cards, transformers, positioning, electrical power cleanup..... all the things mentioned in previous posts. As for the refresh rate - on some video cards (and their drivers), there are sometimes multiple places where the refresh rate is set - one for the monitor itself, and one for the max refresh rate allowed by the video card. The names, locations and such vary, but they DO exist. Go through ALL menus and options no matter how silly it might seem, and note what can be changed, and where. HTH, Bob
    1,070 pointsBadges:
    report
  • MrItchy
    If you are unable to locate a currently-active source of interference, here is another thought. The residual effects of previous room contents can linger long after the room has been converted to new uses. I can think of one example where a user set up a computer in a room that was previously occupied by the local chapter of an audio engineering society. The presence of so many speakers eventually altered the magnetic field of the structural steel surrounding the room, and the monitor was practically unusable until the room was degaussed. Interference of this sort would probably show up as distortion in colors and geometry, but may also affect the perceived flicker. Regards
    0 pointsBadges:
    report
  • HumbleNetAdmin
    Now thats a novel, if not interesting idea!
    0 pointsBadges:
    report
  • LindaS
    If there is a fan of any kind near the monitor it will cause it to flicker.
    0 pointsBadges:
    report
  • LSTEVENS
    I had one that flickered and found out it was a florescent light that was near the monitor. I've also found that a cell phone or other wireless device will make some flicker. My electric pencil sharpener makes it go crazy when I use it too.
    0 pointsBadges:
    report
  • LSTEVENS
    I had one that flickered and found out it was a florescent light that was near the monitor. I've also found that a cell phone or other wireless device will make some flicker. My electric pencil sharpener makes it go crazy when I use it too.
    0 pointsBadges:
    report
  • Jlnewmark
    Now that is fascinating and potentially useful! I do happen to have my cell phone cradle next to the monitor. I'll move it and see if it helps. Just to reiterate -- this is a FLAT SCREEN monitor, not a CRT. Thanks! I'll let you know if it works.
    0 pointsBadges:
    report
  • Ve3ofa
    Saying that it is a flat screen monitor does not imply what technology is being used (LCD/CRT). Noticable flicker is something that is usually caused by outside the computer interference. Flourescent lighting causes more flicker to be a problem more so than incandescent lighting because the light actually pulses from flourescent tubes while incadescent lighting dims and brightens (a stop action camera confirms this). At 60hz display refresh the cause of flicker is the slight difference in lighting and display screen brightness (pulses up and down) (try taking a picture of a television screen someday) the slight difference in frequency of the monitor display (or the delay involved between the dimming of the lighting and of the monitor is what causes the noticable flicker). It may be so slight that the normal humans eyes do not register this (persistance in the retina) but it is registered by the brain. Some people can filter this out subconsiously with others it causes headaches (migraine sufferers have it the worst) this is analagous to people listening to a poor audio system and people listening to a high grade audio system (personally I find audio distortion annoying and tiring after a very short exposure). Even though I couldn't consciously hear the difference between 2 amplifiers I found the amp with the lowest distortion the one I found most comfortable listening to for extended periods of time) and I'm not really an audiophile. An LCD monitor having more persistance (slowly dims and brightens like incadecenant lighting) reduces eye strain considerably for office workers (also the screen being flat we don't have to worry about reflections as much). You can try the fine screened display covers or adding an incadescant light behind the operator but which does supply some lighting to the display. (it doesn't have to be much)
    80 pointsBadges:
    report
  • Jlnewmark
    Sorry. It's an LCD screen, now about 2 years old. I will check the light -- I don't recall if the single bulb we've got in there is incandescent or a compact halogen or compact fluorescent. Thanks for the tips!
    0 pointsBadges:
    report

Forgot Password

No problem! Submit your e-mail address below. We'll send you an e-mail containing your password.

Your password has been sent to:

To follow this tag...

There was an error processing your information. Please try again later.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Thanks! We'll email you when relevant content is added and updated.

Following