well at the same time about them being completely dry before turning them on you need to make sure theres completely no juice left in it any where weither it be in a capacitor, cmos battery or something of the sort. you can still fry some thing when its not plugged in all un hooked.

like i said before i tested the capacitors and many different points on the board to make sure it had nothing left in it.
also if this wasnt some for of cooking oil looking sort of stuff and just dust i would have used a short brissle paint brush and some compressed air with a blower attachment on it


Graham Mitchell post a pic of this board.