I've recently experienced a very strange problem in which my CRT monitor has been flicking constantly, at times it is barely noticeable, at others, it makes viewing the monitor extremely difficult. At first, I suspected the monitor was breaking down. However, another member of my family also owns a computer and I noticed that their monitor is behaving in exactly the same fashion. Even the strength of the flicker seems to match on both monitors. Given this fact, it seems highly likely that the cause of the problem is external, probably electrical. The computers aren't particularly close to each other, one upstairs, one downstairs.
I've lived in this house for 17 years and never had any problems up to the last few months. I can think of only two changes that may be causing this. We have recently been experiencing power cuts very frequently and an engineer put us onto another supply line, apparently we were the last house on an electric power run previously. Secondly, we have recently had an extension built which also required electrical power. It's possible that the wiring to accommodate this has caused this issue. However, the power drain in this house seems not to increase/decrease the monitor flicker.
I know this is very vague, but does anybody have any idea if these issues may of caused the problem? If so, what could I have done about it? I know the effects of magnetic interference is considered dangerous and naturally don't wish to be exposed to this any longer than necessary. The health and well-being of my family has to be consider.
Any help anybody could provide would be greatly appreciated.