Monitor Discoloration When Cab is Turned

[porkins]

I have a cab with a horizontal WG monitor inside. I have had no discoloration problems with it the last several months I have had it in the same location. Suddenly, there is now a discoloration (blue area is purplish to red) on the right side of the monitor. Looking inside the cab, that side of the monitor is the side that has no metal mounting plate between the monitor and the wood cabinet. Normally, I would think it just needs degaussing. The monitor has an auto degauss, however. Additionally, if I TURN the entire cab a quarter turn so that the right side is pointing more away from the wall, the discoloration goes away. If I start turning the cab so the right side points more towards the wall, the discoloration gets much worse, with the affected area growing, and going more towards red from purle (and the original blue). If I turn the cab so that the LEFT side of the cab faces the wall, it looks normal. No discoloration on either side.

The only thing I can think of about this problem is that there is suddenly some kind of EMI in the wall that was NOT there before, and it is being blocked by the metal monitor mounting, but affecting the right side since there is no metal there. Does that make sense? What can I do to fix the problem? Can I add shielding? What should I get, and from where?

I'm also trying to figure out the actual CAUSE of the EMI. The only thing I can put my finger on is that we had a lightning strike recently. It only knocked out the control board on our AC, one of our thermostats, the HDMI connection on one of our cable boxes, and the power adapter for the wireless bridge I was using for the PC inside this cab. The wireless bridge itself is still fine. The monitor itself was unplugged at the time, so it should have been completely isolated. I even tried completely unplugging all electrical devices in the area of the cab, both upstairs and downstairs, but the EMI is still present.


Any insights you have, I'd really appreciate it! Thank you!

[gryhnd]

Try cycling your breakers off one by one to see if it's related to an in wall ACV line.

if so, then work on disconnecting individual items powered by that circuit. You might find an item that was compromised by the strike.

[qrz]

lightning produces a strong em field that can , and many times does, leave a residual magnetic field .

a thorough manual deguassing of the monitor and adjacent wall may nuetralize the offending magnetism.

be persistent !!!