The word "elcos" means capacitor, right? In this case, the problem may be that a poor job was done. However, the logic board was probably washed by the previous owner as part of the attempt to fix the machine....

I am not able to advise you further about how to test/ repair these components but there are others among us who could.

I will say that in my case, capacitor leakage was particularly noticeable in the area where the main power connector plugs into the board. It had bridged the large traces visible in that area. Take a look and see if yours is the same. It is possible that the previous owner did not wash the board as a whole, but just cleaned around local areas and missed this one.