We have a League Champ which is almost identical.
There is not much to the games really so you’ll be looking for general condition. Does everything look complete. Do all pins retract/drop. Does the DMD look good. Nothing cracked or broken.
You can put it into switch mode and make sure all PF switches work.
Boards are standard WPC and easy to repair.
They are fun games and we really like ours. Good luck.