Can an ungrounded power line damage computer components & networking devices? My answer: Some people say probably not, but I say yes definitely it can over a period of time! I had my computer unknowingly plugged into an ungrounded outlet for a bit over two years at the house I'm renting. After the first year I remember my computer died one morning when it wouldn't do anything when I pressed the power button. It had an amber colored light that appeared on the power button instead of the usual green. I soon found out that my motherboard and power supply needed to be replaced. Now a year and a half later I still didn't know the electrical outlet was ungrounded!! It was only last week that I heard light popping sounds coming from inside my computer! I knew the sounds were unusual so I opened the computer case while the computer was running. When I leaned my forearm against the computer chassis I felt tingling on my arm! It was not static electricity, but was a steady tingling sensation which told me I had a ground problem! I then looked at my surge protected extension cord and noticed the ground light was NOT on. I then tested the outlet with a plug-in outlet tester I had and sure-enough the tester indicated that the outlet was NOT grounded even though the outlet was a three-prong outlet! I then took my tester and checked the other electrical outlets in my living room. I was lucky to find one that WAS grounded so I moved my computer equipment, TV and components to that outlet. Guess what happened next? The popping sounds stopped completely, been a week so far and when I put my forearm now against the computer chassis I no longer felt a tingle! I believe static electricity builds-up inside the computer chassis possibly from cooling fans and who knows what. When the current has no-where to go I think that's when damage to components begins possibly? When you hear light popping or arcing sounds or feel a tingle when you touch your computer chassis with your wrist or forearm - that can't be good for the computer? Right? Only makes sense? As to myself I will never again plug my computers, monitors, components and TV equipment into an ungrounded outlet! To me doing so would only lead to component damage if not failure over time.