Another Bally invention, the mushroom bumper is a really fancy target that feels very satisfying to hit. How they work and common problems.

Originally known as 'Flipper Zippers', this feature allows the flippers mounted on the playfield to 'zip' together, closing off the outhole. The feature is pretty simple under the hood. One of Bally's innovations during the EM era, pioneered by Ted Zale.

How to take apart a flipper and change them. The same basic rules apply to any EM pinball machine with flippers.

Flippers have undergone a bit of change since the beginning of the flipper era (1947). Different designers had different techniques for using the flippers, and they certainly changed the face of pinball. I also discuss the basic pieces of the flipper mechanism.

What is a transformer? What purpose does that heavy thing do in your game? These questions and more answered!

Wanye Neyens was a prolific designer through much of Gottlieb's woodrail and metal rail EM production. His career spanned at least 179 machines (according to the IPDB, 177 machines made it to production). He is 97 years old today, July 29, 2015. Happy Birthday, Mr. Neyens!

Some of the basics about how to construct a circuit, how the circuit actually functions, and how to measure and calculate the values of Votage, Amperage (current), and Resistance.

How to use a multimeter to troubleshoot various aspects of a game. A bit of a small electical/electronics crash course in how current flows, what to expect, how to change your settings appropriately, and how to zero out your meter.

The final set of switches on the control unit govern the search process. Everything from the release of the search disc to the lockout of footrail buttons happens here. The control unit is complete - from switch stack A to switch stack ZB!

In our next-to-last episode detailing the workings of a Bally bingo control unit, we examine the switches necessary for the operation of the payout. When a winner has been determined, the machine has to have some way of stepping up the replay meter in the backglass.