Question PC sometimes won’t boot, (New PSU, Maybe not powerfull enought)

Dec 27, 2019
First of all, I want to apologize for my bad English.

Hi, as you see in the title my Pc sometimes wont turn on, even with new PSU.
I recently bought a RTX 2060 Aorus Extreme for my Pc (i5-4460 , 1x8gb Ram, Gtx 1050 2gb, lc550w psu)

I used my pc for about 2 days and when I was going to turn it on, it simply wouldn’t.
I tested my LcPower 550w on a old pc and it worked, so I tought it wasn’t powerful enough to power my pc. I talked with a friend and he recommended me to buy a Seasonic m12 2 620w Evo Edition. When I putted the new PSU on my PC, nothing happens, but then 30 minutes later it started worked again.
In the following day, the same problem happened, my PC wouldn’t boot up (No Fans spinning at All, no LED’s, no Nothing, same as before).
I talked to a Professional, who told me that the problem probably was that the 12V Rail Ampers of the Seasonic PSU weren’t enought for my Pc Specs ( +12V 48A ; -12V 0.8A )

However I have seen several pc builds with similar specs, including similar PSU, so I am very confused.
Can someone help me?