Pinball Machine Anatomy: Every Key Part Explained
Pinball machines look simple from the front glass, but underneath they're a tightly choreographed mix of mechanical, electrical and electronic parts. Knowing what each component does is the first step toward playing better — and toward diagnosing problems when something stops working. Here's a plain-English tour of the key parts of any pinball machine.
1. The playfield
The playfield is the main playing surface the ball travels across. It's tilted roughly 6 to 7 degrees so the ball naturally rolls back toward the flippers. Beyond the artwork, the playfield holds everything the ball interacts with: bumpers, targets, ramps, lanes and hidden shots. On solid-state machines from the 1970s and 80s, everything on the playfield is wired back to the boards in the backbox — which is why a single board fault can make large sections of the playfield go dead.
2. Bumpers
Bumpers are the round (sometimes triangular) targets that kick the ball away on contact, adding speed and unpredictability. Passive bumpers are simple rubber posts that just deflect the ball. Active pop bumpers use a solenoid to snap the ball away with force, and they're usually lit and paired with a sound. When a pop bumper goes weak or dead, the culprit is often the coil, its diode, or the driver transistor feeding it — the same chain of parts you'll test on most playfield mechanisms.
3. Flippers
The flippers are the player-controlled paddles at the bottom of the playfield, fired by the buttons on the sides of the cabinet. They keep the ball alive and let you aim at specific shots. Flipper strength depends on healthy flipper coils, clean switch stacks in the buttons, and steady voltage from the power supply — weak flippers are one of the most common complaints on older machines.
4. The display
The display, mounted in the backbox, shows your score and game information such as balls remaining and current objectives. Displays evolved from simple mechanical score reels, to gas-plasma and dot-matrix displays (DMDs), and finally to the LCD screens in modern games. On classic solid-state machines the display is driven by the CPU/MPU board, so a blank or garbled display is frequently a board or power problem rather than a display fault on its own.
5. The plunger (ball launcher)
The plunger is the spring-loaded launcher that puts the ball into play at the start of a ball and after a drain. Many games let you control launch strength for skill shots. Some later machines replace the manual plunger with an auto-launch coil triggered by a button.
6. Ramps and lanes
Ramps and lanes guide the ball along set paths across the playfield. They're used to reach areas that are otherwise hard to hit and often trigger special modes or stack up bonus scoring.
7. Targets and switches
Targets — stationary or drop targets — are meant to be hit to score points or trigger events. Switches are sensors placed all over the playfield that detect the ball passing by and tell the CPU what's happening. A single stuck or dirty switch can confuse the game logic, so switches are one of the first things to check during troubleshooting.
8. Multiball and kickers
Multiball features release several balls at once, multiplying the chaos and the scoring potential. Kickers (also called ejectors or kickout holes) use solenoids to suddenly launch the ball back into play at speed, adding another layer of unpredictability.
How it all comes together
Every one of these parts plays a role in what makes pinball fun: the interaction between mechanics and electronics is what makes each ball unique. It's also why repair work is so logical once you understand the layout — a dead mechanism almost always traces back through a switch, a coil, a diode, and a driver transistor on a board in the backbox.
If you'd like to go deeper on the gameplay side, read our walkthrough of how a pinball machine works, ball by ball. And when a machine won't power up or a section of the playfield goes dark, our guide to diagnosing a pinball that won't turn on walks you through it step by step.
Most of the faults above lead back to the boards in the backbox. On classic Gottlieb, Bally and Williams machines, a modern plug-and-play replacement CPU board can bring a tired machine back to life without the original battery — and without the corrosion that eventually kills so many original boards.
