First of all I've never posted on one of these before so hi there.

Second hopefully somebody can help me.

I have a Mitsubishi Diamond Pro 930 SB monitor running on an NVIDIA GeForce 5600 in XP.

The monitor has developed a fault where is is now covered by sort of green haze. This hasn't been a gradual thing but was fine one day and then green the next. I have tried degaussing and adjusting the monitor colour settings but nothing seems to be working. :eek:

Does anybody have any idea what is wrong or what I can do to fix it? :confused:

Thanks in advance,


I dont know if I recommend this, maybe as a last resort, but I know people that, if this is the same thing you are talking about, have used a magnet on their monitor and dragged the green off. Usually that kind of thing is caused by a magnet as well. Before you try using the magnet, try slowly rotating the monitor so that it is upsidedown, and then bring it back to normal. Try that a few times until it works, otherwise, use the magnet thing as a last resort. I believe this only works with CRT monitors. Goodluck


Since you say you tried "degaussing" the CRT, that pretty much rules out magnetic influence. Magnetic contamination on your CRT will usually appear as a patchy area with colors (such as green) over the image, but not the whole of the screen.

Your CRT has three color guns (red, blue, & green). Sounds to me like one of the guns is dead. By that I mean the filament is probably open and no electrons are being emitted. You can check this a few ways depending on your expertise. The easiest would be to simply connect your PC to another monitor. If it works OK there, then your PC and all of it's components are fine and your monitor is faulty. There are test sets to check the CRT, but you probably don't have access to them. So the next best thing you can do is to open the case (power down before doing this). Be careful not to touch the CRT backing as you may experience a high voltage shock from the annode area (thick wire with suction cup attached to back of glass). The guns are located in the narrow diameter neck next to the connection point. With the case removed, turn the monitor back on. Look into the neck area and see if you can distinguish three separate red glows (the filaments). If you count less than three, you've identified a bad gun and the CRT needs replacing. (Today, it's a lot cheaper to just buy another monitor).

Good luck. Hope this helps. Let us know.

Ok. Guys thanks a lot for the help.

The green is evenly spread over the whole screen and so I'm guessing is may be the blown fillament.

Will try the magnet as a last last resort if nothinng else works though. Thanks for your help again. Is appreaciated.


I thought you had already "degaused" the CRT screen??? Perhaps you do not understand what degausing is. Using a magnet will not work unless it's one heck of a large magnet. What is needed is a degausing coil. This is a series of tightly wound, small diameter wire, formed as a coil around a core that is completely circular in shape, and plugs into the house AC outlet. The idea is to use it to "remove" any magnetized areas which may be causing the discolored patch(s). Some CRT devices like top end TV sets, have an automatic degausing feature which works at turn-on, but I've never seen them on a computer monitor.

By the way, the procedure to degause is to hold the coil in front of the center of the screen, such that the coil is parallel to the screen surface (and not at a right angle). Starting distance should be something like 1 to 2 feet away. Then plug in the coil and begin rotating the coil in a circle which covers the entire CRT screen and at the same time back slowly away. As you do this, you should see colors changing on the screen. As you back away, the magnetized patches will disappear and your picture will be pure again. When you are about 10 to 15 feet away you should see no more influence of the coil's magnetic field on the CRT's screen. At that point, turn 90 degrees to the side with the coil and disconned the AC from it. (You may need someone to plug in and disconnet.) It's important that the coil is at 90 degrees when the power is disconnected because there will be a surge in magnetism as the current collapses to zero though the coil. Too close and at the wrong angle, and you'll magnetize the CRT's screen and have to start all over again. Degausing coils can be homemade or purchased. If you have a TV repair shop nearby, they probably have one you can borrow.

In your own words, your entire screen is green, so it's nothing to do with magnetized areas and degausing will not work. Forget the magnet. It will just make things worse.

As is clearly fairly obvious I'm afraid I have very little idea at all. If the magnet will not work I won't bother.

Thanks a lot for the help, I would have had no clue at all without it. It is much appreciated.


You're welcome! Sounds like you probably need a new monitor. They're pretty cheap now days. Best way to purchase is to find one that you like and then go to and enter the make & model. Bizrate will find every place on the Internet that sells that monitor and list them with pricing. Then you can sort the list by pricing, or by reputation, etc. There will be links to the sale site. Then look closely at the product details on that web site. Some sites offer free shipping. (I purchased a 19" Viewsonic LCD which retails at $499, for $324 and got free 2nd day FedEx shipping this way.)

CRT displays are really cheap because they are on the verge of becoming obsolete. Flat panel displays are now the way to go. Here's some things to ponder when choosing a new monitor.

ASPECT RATIO: The standard proportion of width to height for a computer monitor is 4-to-3, although some monitors that double as TV's have a wider format of 16-to-9, designed for viewing movies or high-definition TV (HDTV) in wide-screen format.

RESOLUTION: Higher resolution yields better image quality. Make sure you are comfortable with an LCD's native resolution before you buy it. Today, I wouldn't consider anything less than 1200 x 1024. (Also make sure your graphics card will support the resolution you decide on.)

CONTRAST RATIO: A contrast ratio of at least 400-to-1 will provide a more dynamically detailed image. The ratio is measured in varying ways, however, so rely on such figures cautiously.

PIXEL-RESPONSE RATE: This measure refers to how quickly a pixel can change colors and is cited in milliseconds (ms). Lower numbers mean you'll tend to see less ghosting or streaking in movies and games. Most panels have response times of 16ms or less; gamers and video buffs should look for response rates of 8ms or less.

LUMINANCE: Luninance, or brightness, is expressed either in nits or candelas per square meter (cd/m2). A measurement of 200 to 250 nits is suitable for most productivity tasks; 450 nits is better for TV and movies.

DIGITAL VERSUS ANALOG CONNECTIONS: LCD's must convert analog signals before they can be displayed. A graphics card with a Digital Visual Interface (DVI) can send the signal straight to the display in digital format - no conversion required. Most LCD's come with an analog input, some have both, and a few are digital only. A digital connection is best.

VIEWING ANGLE: Brightness and image colors shift if you view an LCD off-center. Make your own observations, if at all possible, of the panel you're considering, and remember that viewing-angle issues become increasingly critical as panel size increases. (Go to a store like Best Buy or Circuit City where you will find several brands, models and sizes with live pictures. Take a look at them all.)

Hope this helps you to make the right decision.

By the way, the LCD monitor I purchased was a Viewsonics Model VX924. Specs are:
Display Size: 19 inches
Resolution: 1280 x 1024
Contrast: 500 to 1
Brightness: 270 cd/m2
Response Time: 4ms
Interface: Both digital & analog

I found it at through

Member Avatar for fsquire

My screen gets the green haze also... I've treid rebooting, scan disk, shutting down for 15 minutes, etc... sometimes it corrects and sometimes I just have to wait it out. One thing I noticed is when I power down the monitor. I get those color bars and they are correct. the red is red the yellow is yellow , etc... so I don't think mine is the monitor. My screen was green for about 10 minutes and as I was writing this the natural color came back... So until I lose my picture altogether, I will put up with it.oops... it's green again...

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