I recently moved into a new apartment. After re-hooking up all of my computer accessories, I’ve noticed that every once in a while, my CRT monitor will “shimmer” during use. I don’t think there’s a pattern to it; seems to happen at random times. Sometimes a half hour or so will pass by before it shimmers. Other times, it will shimmer for up to a minute at a time.
I’m assuming that there’s some kind of interference that’s causing this. However, the CRT is in the corner of the bedroom, away from any other power sources,and is plugged directly into a surge protector. I thought about perhaps the shimmering occurring as a result from the refrigerator or TV turning on, but I disconnected them both and still noticed the occasional shimmer. Someone in a chat room mentioned that I could get something called a line regulator which will shield against surges in the apartment’s electrical supply.
Does anyone have any ideas about what could be causing this, and what to do about it? It’s not a huge issue, as it doesn’t happen all the time, but it does get a bit annoying at times, and if the solution doesn’t entail doing much (or costing much), I’m willing to try it. Thanks!
It kind of sounds like the degaussing circuitry is kicking in from time to time. It’s only supposed to degauss when you turn on the monitor after being off for at least several minutes, But if there’s a defect in the switching circuit, this could be the result. Could also be a cell phone, possibly.
Actually, that’s what the shimmering resembles. I did try manually degaussing the monitor when this shimmering occurs, but it does not seem to help. I’m wondering if the degaussing circuit is starting to fail inside the monitor. This CRT monitor is about five or six years old, IIRC. Maybe it’s just starting to fail… :rolleyes:
Right now, my cell phone is in the other room, but the shimmering still occurs from time to time.
What refresh rate is your monitor set to? It’s generally recomended that you put it above 75Hz for CRT screens so you don’t see the “shimmer” as it updates. But some older monitors or graphics cards don’t support it, or only at low resolutions.
You can check and change it on windows systems by going into the advanced settings of your display properties.
You don’t have to worry with LCD screens however as they work differently (however generally have a slow refresh).
Your refresh rate is probably pretty low, then. I’ve noticed that it’s much easier to see a monitor flickering when it’s viewed out of the corner of my eye. Even worse, the default refresh rate of 60Hz will quite literally give me a headache, because I can see it flickering even when I’m looking straight at it. I always have to have my refresh rate >=75Hz for it to be tolerable (in fact, it’s normally 85Hz).
I think it could be due to small dips in current, or “brownouts” in your power supply, activating the de-gaussing circuitry. This loss could be caused by a loose plug, strong winds outside, or your neighbors activity. Most power surge protectors don’t do anything except prevent dangerous upward spikes in power, so they wouldn’t help in this situation.
I used to have a 17’’ CRT located directly next to a big 36’’ TV set. When the television was turned on, the monitor would shimmer. The effect looked very similar to degaussing but possibly slightly weaker. I always assumed some transient electromagnetic field from the TV was disrupting the monitor somehow, but I suppose its possible that an actual degaussing was triggered by the power drop; I believe the devices were on the same circuit.
It’s set to 85Hz. I did not notice this phenomenon at my previous residence, only at my current apartment.
I think you are right about this. I’ve noticed that the lights also dim momentarily just at about the same time I notice the shimmering. Hmm, I don’t suppose there’s anything that can be done about this, is there…?
If the problems are being caused by line voltage dropouts, then connecting your system to an Uninterruptible Power Supply (UPS) will alleviate the problem. UPS units will supply a clean 120 VAC for any input from about 85 to 140 V, typically. Plus, if the power goes out completely, a properly-sized unit will give you about 5 to 10 minutes to save your current work and properly shut down your system.
Since you mention this is an apartment, is the monitor near a wall shared with another apartment?
At work, I get a “shimmy” on my monitor when the monitor in the adjacent cube is turned on. The power up seems to emit a brief magnetic pulse, which can affect other monitors in fairly close proximity (a foot or two seems to be the range). If your neighbor has an identical floorplan, it’s probably reflected across the shared wall, and they may have their computer in the same spot (especially likely if the room is a den or office).
Could this have something to do with it? When I got my new monitor in August, I noticed that it did this, but it stopped after a week or two. I’m wondering if setting it up (or more likely, not being set up for X amount of time) is a factor.
I am thinking of purchasing an LCD in the near future. If I were to purchase an LCD, I presume that this “shimmering” problem would go away (since there is no anti-gaussing involved with LCD’s)?
You mentioned that the computer is in the corner. Whats on the other side of the wall? It isn’t the neighbors kitchen is it?
I noticed a strange shimmer when we first got out computer and found it only happened when someone was microwaving something. Yep the microwave was on the kitchen counter on the opposite side of the wall. We just moved the microwave.
