Screen Problem

Change channels. Or, you could try this method from:Shift Key Dont Work

I'd do some experimenting. Hmm, is the "heater machine" just an (almost standard?) heater for room heating, or is it some special medical device. (I guess in an operating room, maybe even a room heater isn't standard?)

• I would suggest changing out the heater, and see if another heater causes the same problem, or
• investigate the electrical connection of both the heater and the video screen--are they both grounded properly?
• what about the signal connection to the video screen--could there be a ground loop? (The shield on the video cable should be grounded at only one end.)
• try shielding the heater from the video screen by taking a piece of grounded conducting metal and putting it in various locations between the heater and the video screen--does that have any effect on the black bar? If so, re-investigate the grounding and then consider permanent shielding of some sort. (Is this a new installation, was this always a problem, or just something that has started to occur recently?)

Take the power cord from the heater and wrap it four or more times thru a large steel metal washer(must be steel or iron), within 1ft from the plug. Make sure the wraps are right next to each other and tape it up to hold it. That should filter the feedback RF that the screen is picking up. If that dosen't work, twist it at least five times per foot with a left hand twist. This also nulls RF interferance. Also, don't use the same outlet. Some crt and flatscreens can recieve interferance inside a metal-encased room such as an operating room.

Make sure your monitor and all wires leading to it are shielded and those shields are well grounded. This true regardless whether your O.R. has isolated power supply. Next is to install a line filter on the power side, since the noise / interference may well be coming from the electronic switching (PWM) utilized to control power going to the heater element. You may also have to verify the grounding integrity in that OR room?

How clean is the power feeding the equipment as well as the screen? A UPS might help.

mains filter