So I have checked and the CPU and socket look perfectly fine, no bent pins, no dirt on socket, so I'm guessing the problem is with mobo rather than CPU. With that in mind I'm probably doomed, aren't I?
So today I decided to finally replace thermal paste in my old HP g6-2270s as it was reaching nearly 90 degrees celcius, but unfortunately after putting it together it had started to give error code for CPU issues. And here is my question: what exactly could have caused that? I have replaced it many times before and it was the first time I have ever done something wrong. It was working perfectly before, but just after this simple operation it stopped working completly. I have low hopes of repairing it, but just out of curiosity I am intrested what could have caused that.