Pc won't boot up

[Destic]

Hey guys a few weeks ago my pc wouldn't start up anymore, the day before it worked just fine.
Components:

GPU:               Nvidea RTX 2070
CPU:                i7 7700k tray
PSU:                MWE GOLD 650 cooler master
CPU cooler:     Cooler master hyper 212 EVO
Memory:           2x Corsair vengeance rgb pro 8GB DDR4
Motherboard:    MSI SLI Z270 plus 
SSD:                 Samsung 860 evo 250GB
HDD:                 Seagate 1TB  

So i whenever i try to boot up my device, the fans start spinning for half a second then stop and the ram rgb continue's to light up, 
This problem only occurs when i plug in either the hdd or ssd with only the sata power cable, if either of those 2 are unplugged the device seems to boot properly just with no disk to boot off to.

I have brought my device to a company for repair and i've been told they tried replacing all parts but the same problem occurred every time. ( i wasn't charged any money since they couldn't find the problem)

He also told me he tried almost everything he knew without any progress such as using a different motherboard with my parts or vice versa.

Things i've tried:
Unplug graphics card
Unplug HDD or SSD
Tried spare Sata power cable that came with the package.
Re-apply thermal paste

 

 

If anyone has any idea about this case i'd love to hear it since i'm running out of idea's