Eeek.. "scraped off some foil circuit" ?!!
What are you using to clean this thing? A knife?
I clean main boards (almost robotically..
) for a living... might I suggest the following for future reference -
1 - Compressed air to get rid of all of the dust bunnies and their offspring.
2 - Follow this with anhydrous (99%) isopropyl alcohol sprayed on with yer everyday handy dandy spray bottle.
3 - Scrub with a horse hair brush, adding alcohol as needed to keep it 'wet'.
4 - Rinse thoroughly with more alcohol.
5 - Allow to dry thoroughly (a
preheated toaster oven on 200 deg F works well)
Don't put the board in the oven when it's cold and then turn it on - two reasons:
A - While it is heating up, the temperature can spike when the elements are on until it stabilizes - potentially damaging the board.
B - Alcohol is flammable. Shut the oven down,
then put the board in to avoid the possibility of fire.
FWIW
Steve