Geek Squad should have been the first red flag.he got in touch with someone from the best buy geek squad ... That the motherboard is looking for 12.2 V power and the Corsair outputs 12.1 V power.
If it makes you feel any better, one of the first computers I built from parts I ordered on my own (Good ol Blue. Celeron 800), I did the same thing. Ended up shipping the motherboard back on my dime, only to have it returned.The issue was that I didn't put the motherboard separator screws in.
Sometimes it kind of gets assumed, and that particular issue can be a number of things. It's almost the exact same symptom of not plugging in the 12v that was mentioned earlier, which my friend whom just built a computer a couple weeks ago had the same issue.
To be honest, I have seen this a LOT with hobbyists building computers (I worked in tech repair for a decade+), and I've never actually seen a motherboard get damaged from it (unless it was DOA from the start before the riser problem was introduced). I'm not saying it can't happen, but if that was the issue, more often than not you just fix the issue and good to go.