Problem: Dead
Purchased a Punch-Out in dead condition. Got it home, still dead. Rocking the game and/or whacking the sides a bit got a brief flash of light on it so I went in and reconnected all connectors. Game then came up right after that.
A little adjustment to the micro-switch arms and the game is playing nicely. Still need to rebuild the joystick as it is stiff and sticks a bit.
Solution: Re-tighten/reattach all (power?) connectors