I always recommend a "good" UPS with AVR be on all computers too. It is not for the backup power during a power outage (that is just a minor bonus) but for the AVR - automatic voltage regulation a "good" UPS with AVR provides. A surge and spike protector is little more than a fancy and expensive extension cord. Note I said "good" UPS.
Is that the same Seasonic PSU through out? Or have you tried a different PSU and the same thing happened? If the same PSU (even though Seasonic is a very reliable brand), you need to try another PSU to make sure you are feeding your components good, clean stable power.
You said your outlets were checked by an expert. That's good, but may not be good enough. An electrician usually only checks to make sure the outlet is wired properly, to include good continuity to Earth ground. And that is good. But did he check to ensure the voltage was within the allowed range?
A couple years ago I came home to hear all my UPS (I have one on each computer and my home theater system) were beeping. Yet I could see the power to the house was on. That was weird. I live in
Tornado Alley so I am used to them beeping during power outages, but never like this. Checking the display panel on the UPS on this machine, I saw the line in voltage was 146VAC! I quickly got out my multimeter and verified that was correct.
It's supposed to be 117VAC ± 10% or a maximum of 128.7VAC Some say 120V ± 10% for 132VAC maximum. Either way, 146VAC was way too much. I called the power company, told them I was a technician and said if they didn't want to buy new refrigerators, washing machines, clothes dryers and air conditioner compressors (things with big motors) for everyone in this neighborhood, they better get someone out right away.
No kidding, within 15 minutes, they were at my door. They verified at the meter out back the grid voltage was 292VAC (146VAC x 2). Within another 15 minute, they had another technician in a cherry picker looking at the transformer on the pole feeding my house. The "tap" had fried and it was not long before we got a brand new transformer. My line-in voltage is now 121VAC. :)
So long story short, while your outlets may be wired properly, you may not be getting the correct voltage and that needs to be verified too.
BTW, for future reference (and verify that expert knew what what he doing) every home and every computer user should have access to a
AC Outlet Tester to ensure your outlet is properly wired
and grounded to Earth ground. I recommend one with a GFCI (ground fault circuit interrupt) indicator as it can be used to test bathroom and kitchen outlets (outlets near water) too. These testers can be found for your type and voltage outlet, foreign or domestic, (like
this one for the UK) at most home improvement stores, or even the electrical department at Wal-Mart. Use it to test all the outlets in the home and if a fault is shown, have it fixed by a qualified electrician.
