Flipperforum

Thanks to Bally's decision to modularize their system, there is a technique you can use to save yourself some headaches when you first power up a machine. This method connects one section/board at a time and allows you to test each board thoroughly before moving onto the next so you can isolate any issues to one board. This method concentrates on the -18, -49, and all stern games rectifier boards. The -54 rectifier board on later Bally games would employ a slightly different technique.

Disconnect all connectors from the mpu, lamp, sound (if present) and solenoid driver boards. Disconnect J1 and J3 from the rectifier board. Leave J2 connected. Check all the fuses for proper values on the rectifier board. Power on the game, watching to see if any fuses blow. Use a meter and test each test point on the rectifier board to ensure proper voltage is present (remember some of the voltages are AC). Get the rectifier board working 100%.

Turn the game off and reconnect J3 to the solenoid driver board. Connect J3 to the rectifier board as well. Power on the game and repeat the voltage tests on all the test points on the rectifier and solenoid driver board. Investigate any suspect voltages and correct any faults found. Keep in mind that the displays use both the high voltage and +5 voltage so it might be a good idea to remove the displays from the circuit, also.

Once the solenoid driver board tests ok, connect J4 to the mpu board. Do not reconnect any other connectors to any other boards at this point. Power on the game; if all is well, you will see the mpu board start its LED flash sequence. This is where the majority of repairs will take place; there's no point in hooking other boards up until you have a solid rectifier, solenoid driver/power regulator, mpu board combination working.

After/if the mpu board is booting, add the rest of the connectors back in. When you add the playfield's connectors back in and power up, listen for any solenoids locking on at power-up. Repair the solenoid circuits before proceeding if any do lock on.

At each step in the chain, be sure to inspect and repair any and all connectors in the circuits. Often the connectors get tarnished and do not conduct well enough for reliable game operation. Do not try to clean or sand any suspect connectors - this is a temporary fix at best and only delays the inevitable task of replacement.

Using this method for powering up the game for the first time ensures that any issues you encounter will be isolated to the last piece you added in. Diagnosing and repairing one board at a time is much simpler than multiples.

Once the solenoid driver board tests ok, connect J4 to the mpu board