First Arcade Game

[Bi11yJ0e]

Just got a Mario Bros game really cheap. The power cord was cut and there's been some mice nest in the bottom at some point. Fixed the cord and it came on. I need to clean it still but here's my question. I can't make out any of the letters on the game. The menu when the service switch is pushed is all scrambled and so is the top of the screen where the score is at. There's no lines or size issues so could it just need the rom chip connections cleaned? Thanks!!