Question No POST, no beep, no display

[CakyTheCake]

CPU: Intel i7 7700K
MOBO: Asus PRIME Z270-P
Memory: Corsair VENGEANCE LPX 1x16 GB DDR4-2400
PSU: Corsair CX450

This PC has 2 years and it worked without problems in these years.
So this problem is born two weeks ago when my friend gives a little hit to the case(but very very little , he literraly touched it) and the pc freezed,
the reset button for the first time didn't work and I removed the alimentation , so i tried everything and nothing, all the leds and the fans turns on but nothing on screen
I breadborded and bought a mobo speaker and first he gived me the memory beeps but then I understood that I attached wrong after all the trials
I sent under warranty old ram and received the replacement but nothing
I get another mobo of the same type but nothing

I tried to follow this guide but nothing
1.Yes
2.Yes
3.Now is breadborded but on the case it always worked so I don't think
4.Yes, it always worked but now is breadborded without gpu
5.Yes
6.I have only one ram
7.Yes
8.Yes if I insert the memory in an other slot it gives me memory beeps
9.Yes
10.Yes
11.There aren't but maybe I don't know how to find them
12.I changed the thermal paste almost a year ago but now I have to buy it if I want ( do you think that i have to change it?)
13.Yes
16.Yes
17.Yes is the first thing that i bought
18.Yes
19.Yes
20.It always worked
21.Yes but i couldn't find the reset jumper but i have also bought a new mobo

So I arrived to the " Silence indicates that the RAM is shorting out the PSU " but I cant understand if the problem is the ram, the mobo or the psu
Have you suggestions? I don't know if i have to buy another cpu or another psu because I don't have a voltmeter and with this quarantine (I'm italian) the pc would
be very useful to not go crazy

 

[CakyTheCake]

Update: even if no one has answered, I did the paper clip test as recommended by corsair support and the psu fan worked, can this problem be caused by a broken cpu?