I have an old motherboard I don't use and am going to sell it. It has some dirty spots that air isn't cleaning. Is Isopropyl Alcohol(70%) safe to use on it? Will it damage the varnish? I was told that it's safe to use on motherboards and won't damage or remove any of the varnish. Is this correct? I have used it in the past on a video card I had and it didn't seem to damage anything or remove any of the varnish at all from what I recall. Just wanted to double check.