Question Pc suddenly has no display to motherboard or gpu

[ZackBros]

Hi there around 2 weeks ago I was using my pc as normal and went to switch it off for the night as always and it was fine but when I went to turn it back on the next day it turns on but I get no display from either the graphics card or the motherboard and I was getting 1 long and 3 short beeps when I turned it on and I looked online and tried everything I could find on it and even contacted Asus who make the motherboard and still nothing so I bought a new motherboard thinking it would fix it but after installing the new one I'm still having the same issue but without any post beeps when I turn it on.

I hope someone can help me with this as I really need my pc working again,
Thanks

I have an intel i9-9900k
Nvidia gtx 1660ti
corsair vengance 2x8gb ram
the old motherboard was an Asus z390e gaming
the new motherboard is the Asus prime z390a

 

[rgd1101]

brand and model of the psu?

 

[ZackBros]

brand and model of the psu?

CORSAIR 850W RMx SERIES™ MODULAR 80 PLUS® GOLD

ive had my pc for nearly 2 years so it was fine for a long time aswell.