Video card looks to be failing, what can I do?

I have a macbook A1342 White Unibody 2010.

It worked ok for a while but unfortunately I was stupid enough to try clean the logic board with isopropyl 99%, because it was a second hand logic board I bought and it had a very strong perfume smell on it.

I though it couldn't really hurt, and just submerged the board for a while (that was probably stupid) and then let it dry for a day. I guess it wasn't that good for it...

When I turned my macbook on it booted fine, but I noticed a icon on the launcher to be totally garbled up in little specks of color. Later I had a full screen with this messed up colors, but after that it just did not happen again.

However, running 3d mark on a Windows 7 install repeatedly made the program crash because of strange errors that definitely pointed to the videocard. This also happened when the laptop just had started (so not a heat problem).

I did try to replace the complete ram to make sure there were no mem errors causing the videocard to misbehave, but unfortunately the 3dmark program still crashed sometimes.

So, I am afraid I just have to give up this motherboard?

Or is there something I still can do?