Thank you for the reply.
To replace mainboard is too expensive. I already started to sell components from the laptop, I just want to try and solve the problem, maybe I can also make it work and try to sell it.
About question no 2. I already agreed with the seller, he will send me a new component because he messed up the order(sent me C1 instead of C0).
I now have to wait another 20 days, the component comes from Hong Kong. :-(