It sounds like a heat problem in the monitor. It could also be a computer graphics problem. Leave either the computer or the monitor on for a while and then turn on the other device. try to discover which is needing to be warmed up. The buzzing and problems with the other RF devices around mean that the monitor or computer is emitting frequencies so it will affect the TV and maybe the computer. I found my computer emits these frequencies. I can't listen to AM radio when the computer is on.