All new parts

There we have it,I bought a new computer box for one of my boards.The board looks fine but there is some dicoloration on the back.Dusty cream color that makes the board look broken across a path between two posts,say red…black.There is power between these points,but will this be bad news later.It is the only other 500mhz board I have.Viaboard a 9000Y BY THE MEM sticks.I read some where about this board.What other points do I check to see if this board is good.