Question Laptop motherboard no power and getting hot

Jun 9, 2020
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Hi everybody,
I have a HP zbook 15u 4G (same as the elitebook 850 4g).
The original motherboard stopped working due to a fail in the CPU so I got a used one from Ebay. Installed it and it appeared to work fine until I realized it was not charging the battery. I started to look around and it sadenly stopped working. I then realized that the charging jack was missing the internal plastic separator thing so I assumed it shorted there. Replaced the charging jack with the one from the old motherboard and it is still not working and it gets really hot, it is not on a specific place, all the copper ground ring get hot.
Any ideas where should I start looking?
Thanks