What Happened?

I was getting a buzzing sound through my Rotel receiver. Didn't matter what the volume was set at or which source was selected. I turned off the power switch to my surge supressor for about a minute, then switched it back on--bingo! The buzzing was gone. I'm just curious if anyone with a more extensive knowledge of the behavior of electricity in audio components than myself (probably the majority of you guys) can explain what might have happened. My amateur theory revolves around some electromagnetic charge being dispelled.
If you are sure that removing power from your electronics did not resolve the buzzing then I would say it was your surge strip. Back when I had access to a dranetz a/c line analyzer I was only able to prove 1 time (out of hundreds) that a surge strip was a severe problem. It was so bad it caused the main in fuse to blow (it was some computer interface) I have been repairing computers since 1976 - computers do not like flakey power. Also I did find they did nothing for impulses - brown outs - and minor surges and only clamped down a surge when voltages reached approx 170 volts. By then most equipt is toasted. That being said I'm referring to inexpensive (typically less than $20 surge strips). If you have an inexpensive strip you may have had a power anomaly that caused some sort of ringing in some device. If the problem re-occurs I would recommend removing power (pull the power cord) from each component for a couple of min each to further isolate the problem