Custom built pc not booting.

[Gendo]

Hi!

Started having issues with my GTX 780 gpu which was still giving an image but wasn't recognised by W10 and would crash the system on occasion, troubleshoot that and the issue got better but still would crash on desktop and some games. Then I've noticed Doom was running out of Ram when crashing so checked and it only had 8GB out of 16GB used but still the full amount recognised, same on Bios which sees both modules but only 8GB available.
So swapped and removed the modules with no success only to find out that now the PC isn't booting even on the original configuration, now the hardware starts but no post, removed the GPU and still nothing.
To note I have no spares to test, any suggestion much appreciated!

 

[VirtualLarry]

Was this a recent build? Out of used parts? Has it ever worked properly?

 

[Gendo]

Was this a recent build? Out of used parts? Has it ever worked properly?

Hi! yes it's a first gen Ryzen build and always worked great, everything new and from good brands apart from the 780 which was used as I don't game that much these days and for 1080p still does decently.
Didn't mention that it all started after a major Windows 10 update and even the OS was acting weird, which I repaired from CMD.