Does your game have an R relay (115 VAC hold relay)? This relay needs to pull in and stay energized all the time in order for the main power supply to the transformer to stay on.

You should be able to push the R relay in by hand, and that should make the game power come on, and also cause the R relay to energize and lock itself on. If you press on the R relay and the power comes on, but the R relay won't stay in the energized position, then you probably have an issue with either the circuit that supplies power to the R relay coil (to be technically accurate, actually it is power to the transformer primary), or you may have an R relay coil that has fried and no longer works.

There are usually anti-cheat switches on both the inside of the front door and on the bottom board that need to be closed all the time for the R relay to get power. These switches will have a large circular weight on the end of the longer switch blade that are designed to cause the switch to open if a player bangs on the door or picks up the front of the machine and drops it (I know, it sounds crazy, but people used to do this on location to try to get free games). Anyway, you'll want to check these anti-cheat switches and confirm they are all making good solid contact.

There is also a tap-off switch that is similar to the anti-cheat switches. The tap-off switch is also mounted on the bottom board, but it is actuated by a small metal rod resting on the cabinet bottom. This switch is designed to shut off the game power if you tap on the bottom of the cabinet. You'll want to make sure the switch blades of this tap-off switch are also making good solid contact.

When you check the above switches, make sure the game is unplugged from the wall outlet. These switches usually have line voltage (115 VAC) on them and you don't want to get a nasty shock. Almost all the other elements inside the machine are running at much lower and safer voltages (25 volts for coils, 6 volts for lamps).

If you check the above switches and they all seem OK, then it's likely that your R relay coil has burned out and will need to be replaced.

- TimMe