a couple of things you can check before replacing the expensive UDN7180.. have a look at resistors R1 thru R7 on the master display board, (the ones to the top left of the display glass) and see if any are getting hot or are burnt. These resistors run the 7 segments of each digit in the player 1 and 2 and master display glass.

 Another thing you can try is remove the connector from player 1 and player 2 score displays one at a time and turn the game on, and see if the others work ok. I have seen it happen where a bad display glass can pull down the segment lines and cause segments to be out in some of the other displays. So for example if you remove player 1 display connector and the player 2 and the master display work ok, then the player 1 display glass is faulty. this fault will cause one of resistors R1 thru R7 to get hot and burn up. Had this same fault on my Stellar Wars