/vr/ - Retro Games

So I got a copy of Metroid Zero mission at a used games store. Everything works except saves are deleted when i power down the system. At an earlier suggestion from here I soldered in a new tabbed battery but it still doesn't work. Only thing I can see that may be an issue is that there is a strange white substance on the back of the board. Picture is the new battery in place to see if I did anything wrong.