Arcade Monitor Wells Gardner problem, help me please!

[MuKuro]

I have a WG K7000 25" wich have a problem with focus only on the corners of screen.
In the center of the screen all it's ok, but around of the screen's center and expecially in the corners there is strange red color like a focus problem. This is well visible when ther are clear script on black screen, the script is surrounded by red color.
I tried to adjust the contrast control or focus control but whith any results.
If someones can help me, let me knoe please.

 

[Pro_Gear]

sounds like a degaussing issue with the monitor.

 

[MuKuro]

Pro_gear thanks for your reply, maybe its so.
From the Monitor manual:
This monitor is equipped with an automatic deguassing circuit. However, if the CRT shadow mask has become excessively magnetized, it may be necessary ti degauss it with a manual coil.
Do not swictch the coil OFF while the raster shows any effet from the coil.

Unfortunately I have no idea how to do this operation frown

 

[chemical]

There's a way you can use a hair dryer or electric drill as a manual deguassing coil.

I forget exactly what it involves. Most likely some way to electricute yourself.