@bogbeat
Really good suggestions above. As mentioned I would replace your outlet(s) with something more robust. Check your outlets for proper grounding and connection by using one of those cheap outlet testers.
Regarding power cables the stock black ones sent with equipment are junk and are only meant to power up the equipment. I was at a demonstration at a dealer where they were demonstrating power cables. A really straightforward set up from an integrated to the speakers. Only one power cable was changed. We started with the stock cable and worked our way up to a $10k cable. This was a very, very modest system with inexpensive monitor speakers. My takeaway was that yes the stock cable was junk and the sweet spot for cables was in the $150 to $500 range (full retail).
As @lak and others have stated the zavfino cables are wonderful. You won't be able to build a cable that sounds as good for the money. I have swapped out three of my power cables for the zavfino and they were cheaper than the cables I was using and sound better. A member of our audio club has also purchased the zavfino cables and they are keepers for him and he has tested and owned more cables than I would ever approach. They had been offering discounts on purchases. The only downside of their cables is that they are stiff and if you are between lengths get the longer one.