CrazyMonitorFilter: Fix my vibrating monitor image, please?

Are there any electronics around that might cause an interference? Some cell phones cause vibration in computer and TV screens.

I have seen that in the old days (386) from a bad monitor port. It's faintly possible it's chips, not salsa.

Maybe it's becase you're eating pretzels while looking at the monitor? Seriously, though, I had that problem with a powered air cleaner plugged into the same outlet as my CRT monitor. It caused a wobbling image. I moved the filter to the other side of the room and the problem went away. If you have a UPS perhaps you could try yanking the plug. This should isolate your computer from the AC line so you can confirm or eliminate the AC power as a variable.

A monitor in a computer lab I watch over started doing something that could be described as vibrating -- my conclusion (after doing most of the things people described here) was that it's dying, and there was nothing I could do about it. Luckily there were a few extra monitors sitting in the corner.

At an old apartment there was some kind of transformer in the courtyard about 10 feet away from my window and it caused the image on my computer monitor to jiggle. Moving the computer across the room solved the problem.

Sometimes, this kind of thing can result from a "ground loop" becoming established between a desktop machine's chassis, and a monitor. If both the monitor and the chassis are equipped with 3 prong grounded plugs, then I think it might be useful to plug them both in to a common outlet strip, and then make sure that strip is plugged into a properly grounded AC outlet. It's pretty common in older cubicle farms, especially those that may have been moved, for the power grounding system to have some problems. http://www.tripplite.com/products/static/ct120.cfm are available to diagnose these problems. Bad grounding often shows up only when some high current demands are made, especially in low humidity conditions. But if you at least get the PC chassis and the monitor chassis tied together electrically, you may eliminate the problem. Getting them both grounded to a common ground point is important to making sure the overvoltage and ground fault protection circuits in the PC power supply work as intended for safety.

I have this problem. I think that the power in my (old) house is inconsistent.

I second the electrical interference idea. It get this problem sometimes when I have a box fan on the floor near my monitor.

My monitor started doing that when I plugged in an humidifier (el cheapo from Walmart) on a plug on the same circuit as the monitor. I think it had some kind of wacky power draw. If you have anything else plugged into the same outlet, or a nearby outlet, try moving it or unplugging it and see if that fixes it. When I plugged my humidifier into a different outlet, everything went back to normal.