To repair the motherboard, you need to change the chip.
The computer's motherboard chip is very fragile, because most of the time it is burned out, so it can only be recommended that you change, rather than to repair you.
Otherwise, your computer won't work, but I've had to pour water into my laptop keyboard before, and the computer repair place told me it burned the motherboard and I need to replace it with a cheaper one that's probably $1,000 less.