Have you cleaned the board with vinegar, water & a toothbrush? Lighter fluid... ummmm, no. Wouldn't try that meself ever. May as well clean off the corrosion with Coca-Cola then. Oh - but that would definitely eat through traces... lol
Did this "resin" as you describe it eat through any traces? Have you reseated any socket'd chips, especially the CPU?? And most importantly... did you dry out the board 100% before plugging it in? lol
Next step would be to check for voltages across the various chips & components. Checking continuity, etc.
