A few weeks ago a transformer blew in my area and the power went out in my neighborhood. The power came back up a few minutes later and everything was okay, but when I turned on my DAW PC the next day (it was off during the power outage), it wouldn't turn on. I thought it was peculiar since it's plugged into a Surge Protector - two of them, in fact (both a power strip and a specific Surge Protector that plugs into a wall socket).
I recently opened up my PC to take a look. No visible damage or smell. No funny-looking capacitors. I removed and disconnected the PSU, a Kingwin 650W and did the "paper clip test" by shorting out two wires in the Motherboard plug with a bent paper clip and it turned on, the fan was spinning.
But I theorized that incidentally or coincidentally, the PSU may have gone bad, yet had enough power to turn on by itself but not the whole computer.
I borrowed my dad's PC and temporarily transplanted the PSU (It's a generic brand 450 or 500W), plugged it in the motherboard and CPU sockets, and turned on my computer.
MY COMPUTER TURNED ON!
I didn't have any drives or the monitor plugged in, I just wanted to see if it was the PSU or Motherboard at fault (I have an ASRock Socket 2011 board, which is still pretty expensive on the used/NOS market). But I heard the CPU fan spin and the power LED on the case lit up - which didn't happen before.
So I assumed my Kingwin PSU may have gone bad. I ordered a 700W Seasonic fanless PSU off of Newegg and it arrived today. I installed it, plugged all the modular cables in (Motherboard, CPU, SATA), checked, double-, triple- and quadruple- checked if all the cables were firmly placed in their sockets, and...the computer still didn't turn on. I even tried turning it on with only the Motherboard and CPU sockets plugged in...still nothing (Yes, I had the switch next to the power cable on the PSU turned on).
I had researched about computers not powering on due to dead CMOS batteries, and my CMOS battery was the same one that came with my motherboard when I bought it in 2012, so I figured it needed replacement. So I bought a brand new CR-2032.
I'm at my wit's end. It may be possible that I had bad luck and bought a bad PSU but what are the chances? I've had over 20 years' experience building my own systems so I'm no noob when it comes to PCs. I have no idea what to do now. I could check the PSU's voltages but I don't have a digital multimeter handy.