Quoted from Pinball-DOOD:I plugged it in! The transistor is fine but when ever I turn it on, the displays are all messed up and the game will say random words.. what has happened?!
You need to post a lot more info if you want help from the tech guys here. Game? What did you work on (CPU, audio/visual, driver board, etc), did you unplug any ribbon cables, plugs etc.