I'm assuming you're talking about Hyper Street Fighter 2: The Anniversary Edition.
Check and see if it's a standard CPS2 setup or one of the black all-in-one boards.
If it's a standard CPS2 board, replacing the A board will fix the RAM issue. If not, the fix is a lot more complex.
If you need a CPS2 A board, PM me (I've got an extra).