I had my computer connected to a green power board. The computer itself is on the master port and the screen, speakers, etc are on the slave ports. When the master port drops below 5 W, ie. when the computer goes to sleep, the slave ports turn off to save power.
I stopped using this setup because I noticed my screen and speakers would occasionally pulse on and off when not in use every 4 seconds. I'm guessing the power board takes 2 seconds to decide when to switch and the master port was floating around 5 W.
I finally realised it coincided with the operation of kitchen appliances such as the kettle and toaster.
Could my appliances be causing enough noise on the line to trip my power board? Is so, what steps and products could I use to prevent this? I'm happy to spend some money, but not so much that the power savings are negated.