Monitor problem(updated need more help)

[Codewiz]

I just moved to a new apartment. It is a nice place. After I unpacked and hooked up my computer I noticed my monitor screen shakes. Not the physical monitor but the image on it shakes and flickers. I have tried different refresh rates. Currently it is set to 85Hz. I have my computer and my monitor hooked up through a UPS. I thought it was caused by the air conditioning cutting on and off but it doesn't always shake when the air is on. The same thing happens with two different monitors. And with a spare computer I have. The only thing that doesn't get affected is my laptop.

Any ideas?


EDITTED: Look at my latest post

 

[WW]

sounds like some electromagnetic interference.

can you move your system to another room to see if it helps? are you really near the power lines or something? the stereo or tv?

could be the power supply to the building too...

see here for more info

 

[Codewiz]

It is a one bedroom apartment. One computer in the bedroom and one in the living area. Both have the same problem. I assume it can't be caused by a problem with the wiring in the apartment since one computer and monitor is hooked up to a UPS which should take care of any power quality issues. One computer is near my TV(within 5 feet) and the other computer isn't near anything.

 

[WW]

I don't think the ups will filter the interference with the mains still working (unless it has such high-end filter compabilities).

But, you can test to see if it's the power supply by running the computer from the ups (ie pull the wall plug). Does the interference continue? if so, then it's emi from some other source, not the power line.

does it happen if you connect your monitor to the video out of your laptop?

otherwise shield your monitor with aluminum foil (just kidding).

 

[BraveSirRobbin]

WW may be correct in the problem is with your AC power in your new apartment.

Get a circuit checker (3 lights in a unit that plugs into an outlet). Cheap at any hardware store. This will tell you if hot and neutral are reversed or if the ground is incorrect. (I noticed some outlets at work were incorrect after we had some monitors blow out).

Another thing, I notice my monitor "shakes" when I print a document to my laser printer. Does your monitor do this constantly?

WW's idea of running off of the UPS will also tell you if the problem is with your AC or isolated to your components. Maybe your laptop works because it runs off the internal batteries even though you plug it in (not sure about this statement!!!).

One other thing, do you have any computer speakers near the monitor? Also sometimes an AC adapter will cause monitor interference if it is near the monitor (speakers usually have an AC adapter and some people plug it in to a power center which is right below the monitor.) If so get an extension cord and move the adapter away from the monitor.

Good luck.

 

[Codewiz]

Nothing has changed in my computer setup except the location. I do have a laser printer but it is not plugged into the same outlet. It does not constantly shake. It is really weird. It will shake at random times. I have pretty much decided that it is not specifically caused by the air conditioning being on. Another thing to consider is the home security system that is installed. Do home security systems send voltage scans over the wiring in the apartment?

My temporary fix has which was suggested on a link WW posted was to lower my refresh rate to 60Hz. It is killing my eyes but it is better than the shaking. I can definately feel the eye strain.

 

[Codewiz]

Damn it. After over a month I am still having this shitty problem. I admit I haven't been trying to fix it everyday but yesterday I had enough. I can't sit at the computer more than 25 minutes without feeling sick in my head and stomach.

Currently this is how I have my main system setup. The effects are also seen on my second computer in a different room.

I have a surge protector that is supposed to have an EMI/RFI built in. I have my UPS plugged into that powerstrip. I have my monitor and computer plugged into the two outlet on the UPS that has battery backup. Everything else plugged into another powerstrip in another socket. I have tried all different combinations of outlets to use.

Here is what I have ruled out:

Laser printer
router
cable modem
TV
________________________

Things to consider: I have an alarm system. It plugs into the outlet and scans all the windows and doors. I don't know exactly how this is accomplished. My air conditioning intake is more than 12 yards from the computer.

The screen doesn't shake all the time when the air conditioing is running. Half the time it shakes when the air is completely turned off.

While my screen was shaking I unplugged my UPS to eliminate the possiblity of dirty power. The screen still shakes when the UPS is unplugged from the surge protector.


This leads me to think it is EMI what I have no idea what is causing it. Unless the alarm system could cause it. I can see it causing the problem on my computer since it is near the actual alarm control center but the other computer is in another room.

Could a refrigerator cause this? It is like more than 10 yards away from one computer and the other computer is in a totally different room.

This this behavior starts and stops then I assume whatever causes it must be cutting on and off.

If the fridge is causing this is there anything I can do to prevent it?

EDITTED: It is not the fridge. Just left the door open to see if it would make the screen shake. It cut on and the problem did not start.

Sorry for the long post.

 

[stevewm]

It could very well be something in a adjacent apartment. EMI can affect things at somewhat long distances.

I had a similar problem with my work machine. After 2 days I figured out what the cause was.

The employee breakroom which is located 1 room away has a pop machine in it. Despite being 1 room away the pop machine still manages to interfere with my monitor when the refrigeration compressor in the machine kicks in.

I have found only one way to fix it. Currently the way my monitor sits on my desk has the rear of the monitor facing the general direction of the pop machine. If I turn the monitor so the side of it faces in that direction the interference stops! I ended up having to rearrange my entire office to get rid of the problem! :|:frown:

 

[Codewiz]

Originally posted by: stevewm
It could very well be something in a adjacent apartment. EMI can affect things at somewhat long distances.

I had a similar problem with my work machine. After 2 days I figured out what the cause was.

The employee breakroom which is located 1 room away has a pop machine in it. Despite being 1 room away the pop machine still manages to interfere with my monitor when the refrigeration compressor in the machine kicks in.

I have found only one way to fix it. Currently the way my monitor sits on my desk has the rear of the monitor facing the general direction of the pop machine. If I turn the monitor so the side of it faces in that direction the interference stops! I ended up having to rearrange my entire office to get rid of the problem! :|:frown:

Well the only thing it could be is something above my apartment. I don't have anyone in the apartment next to me. This is really driving me crazy because it is almost impossible to narrow down.

Does anyone know if an LCD would be affected by this? My laptop isn't affected by this and it is setup like 4 feet from my desk. If that is the case then I will ask for an LCD for my birthday or christmas. Or if I get a job sometime soon then that will be my first purchase. I am a programmer so this is killing me.

I know this is sounding silly but what if I enclosed the top and sides of my desk with cardboard lined with aluminum foil. Would that reduce the EMI I am experiencing?

 

[stevewm]

LCDs are completely different tech from CRTs.

They are not affected at all by magetic interference. This is why your laptop LCD is not affected

 

[SWirth86]

I used to have a slightly similar problem.....the left side of my screen would shake, but only at 'random' times. Later on I figured out that 'random times' were when the stereo was on, which is about 6 inches from the monitor I moved it about a foot away and the shaking went away. Also, once I had a fan (small one, about 8") next to the monitor, and it made it shake/wobble. Is there anything that would block interference? Hope you find a way to fix it

 

[Codewiz]

Well I decided that I will just buy an LCD monitor since i wanted one anyways. I don't have the money for it so I am selling my cisco aironet 350 access point to pay for it. I would rather run cat5 to my laptop than suffer a shaky monitor.

Any recommendations for a 15in or 17in LCD that has a DVI-I input?

 

[SWirth86]

Originally posted by: Codewiz
Well I decided that I will just buy an LCD monitor since i wanted one anyways. I don't have the money for it so I am selling my cisco aironet 350 access point to pay for it. I would rather run cat5 to my laptop than suffer a shaky monitor.

Any recommendations for a 15in or 17in LCD that has a DVI-I input?

15 Inch Part One
15 Inch Part Two
17 Inch Part One
17 Inch Part Two


EDIT: I don't really have a recommendation since I own a CRT, but this should help.

 

[BenRosey]

Just for fun, go buy some chicken wire (or equivalent) at the local store and enclose your monitor in a Faraday's cage (if I remember right, that's what it is called). It will shield out all of the EMI. That is clearly the problem.