Milk spillage, after logic board bake it works but turns off randomly.

Last month i had spilt milk onto my laptop but i had seen a solution online were you have to bake your logic board, so i removed the logic board and baked it for 10 mins at 90℃ and replaced the thermal pasted etc. It worked perfectly fine for a whole week! Until one day it randomly shut down completely and then didn't turn on again until about half an hour later. This has been going on for some time now and every time it shuts down i have to wait between 20-60 mins. until i can turn it on again and then it only lasts about 30mins-12 hrs until it shuts off again. plz help and feel free to post any useful comments.