laptop no post

[Alexperson123]

Ok to start off here, this type of repair (appears) to be new territory for me. I am trying to fix this HP Elitebook x360 G2 that I received that won't post. When I power it on the fan starts to spin at full RPM and someone I know said they have seen this happen before if it's having cooling issues and told me to try cleaning the fan and thermal paste and reapplying it which I did and got nothing out of it. I believe there is something wrong with the main board and I am trying to find a schematic and a boardview to figure out what the voltage should be for what and what should or shouldn't be shorted. I'm aware that that's already a very difficult task in of itself, but I gotta learn how to at some point right? I've spent quite some time trying to look and found a couple of sites that have both the schematic and boardviews but not for this computer. Anyone know where I can go to find this or know of other models that have practically the same layout that I can use that instead?
 

If you have other ideas that could fix this I'm all ears. The computer doesn't me any kind of error code either so I'm trying to guess and check.

 

I have a lot of experience in fixing computers but not to this level, I tend to stick to more part replacements and fixing the software side of the computers