3 Monitors Shake at high Freq.

[Manngc]

Hey,I just recently bought a 21" monitor(Optiquest Q115). However, I noticed that the refresh rate was set at 60Hz, so I decided to increase it. When I did that, the picture immediately got horribly shaky and jittery. It didn't matter what rez or freq. over 60, the same results and on 2 different computers (Both at home, with different video cards).

So I thought the monitor was broken and had a different one shipped (Viewsonic G810). This one does the SAME EXACT THING!? I also noticed that my brother's 19" Dell Trinitron also suffers from this phenomenon (hadn't noticed it before). So I doubt all 3 monitors are broken, so what can it be? EM interference?

Thanks for the help.

Mann

 

[GoSharks]

You are correct, magnetic interference will give the symptoms you describe. Anything that creates a magnetic field may influence your monitor. Fans, motors, large speakers, elevators etc. We had a similar problem when we moved into our offices a couple of years ago. What we found was that an unbalanced AC current created the magnetic the fields. Current normally flows along the live and neutral wires, which are close together in the cable and so their magnetic field cancels out. The neutral/earth short can cause current to go in a large loop rather than heading back the intended way created the magnetic field.

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com

Jim at http://www.monitorsdirect.com

 

[Manngc]

Ok, so if it is EM interference...how do I fix it?
Suggestions would be helpful...


Mann

 

[GoSharks]

You must find the source of the magnetic interferance and remove it, or move your system to another location.

Jim

Jim at http://www.monitorsdirect.com

 

[Manngc]

Well, I just got through moving the monitor all over the house with no results. I'm fairly sure that the EM interference is due to the large power lines that run in are backyard about 100yards away. Now I need to know how to shield the monitor...

 

[GoSharks]

Unfortunately there is only one way I know of to shield a monitor and its not cheap or guaranteed to work 100%. The only way to shield magnetic fields is using an alloy called Mumetal.

For more information on Mumetal and monitor shields look at the following link.
http://www.mushield.com/material_specs.html

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com


Jim at http://www.monitorsdirect.com

 

[Manngc]

I did a little research on that shielding stuff. WAY too expensive, and just plain UGLY. Well, I guess I'm stuck with 60Hz (which really doesn't bother me much). However, is there a way to LOCK the refresh rate at 60 Hz, so that games (such as Diablo II) and other programs don't change it? That would basically solve my delima.

Mann

 

[Red_Zealot]

If you run Win2k or XP, you can lock the refresh rate using the nvreffix refresh rate fixer....

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