Logic board problem (but im using it now)

So, here is my problem if you can help me:

i`m using now my macbook pro mid2012 that most of the times it doesn't boot anymore, but rarely does like today so it makes me to think that the logic board is not dead

Two years ago it suffered with liquid damage but has been working since then

The battery has reached the 1000 cycles also

I`m not willing to pay for the repair or for the replace so i was wondering, do you think that it worth the risk of alcohol cleaning the logic board by myself like some videos of liquid damage repair on youtube and/or buying a new battery to test in it?

(sorry my english)

thanks