Can I use ethyl alcohol to clean a logic-board?

Diego Lo, if in an absolute bind, yes you could use ethyl alcohol. Just make sure it does have a high proof and does not contain other chemicals. Unlike ethyl alcohol, isopropyl will separate when in a mixture (water for example). It will also evaporate easier than ethyl alcohol. You can also just clean the board with distilled or sterile water. Most regular dirt can be cleaned with sterile water well enough. Make sure that whatever you are cleaning does not have any power connection, and that you do not power it back up until the board is absolutely dry. Hope this helps, good luck.