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Wico Corporation was the world's largest supplier of parts and accessories of all kinds of coin operated equipment before going out of business in the early 2000's. They covered all types of amusement equipment, jukeboxes, and vending machines much like Happ Controls does today. Wico even manufactured their own assemblies and circuit boards for different applications. In the late 1970's, pinball was hot and so was the home pinball market. Wico decided to jump on the bandwagon, and produce their own home model pinball machine, "Big Top".
- Big Top, November 1977, catalog # 15-2001
Backglass and playfield of Wico "Big Top" home model pinball machine.
3 Technical Info
Overall assembled dimensions: 63" high by 43.5" long by 20.5" wide. Weight 143 pounds. Big Top used a combination of classic Stern, Williams, and Wico's own parts to build this machine.
- 15-8014 Pop Bumper Coil and Sleeve
- 15-8017 Slingshot Coil and Sleeve
- 15-8020 Flipper Coil and Sleeve
- 15-8023 Chime Coil and Sleeve
Some brand new replacement Wico coils are available from Marco Specialties.
View of the underside of the playfield. The bottom panel of the cabinet had literally fallen off in this picture.
4 Problems and Solutions
4.1 MPU Board
The Big Top game board is merely an electronic calculator and does not use a microprocessor at all. It is all TTL chips and a few transistors.
- PL1/SL1 (upper left corner) Playfield switches
- PL2/SL2 (top center) Chimebox circuit
- PL3/SL3 (bottom center) Cabinet switches
- PL4/SL4 (upper right corner) Board power input and insert lamps
4.2 Power Problems
The power box assembly contains the power transformer, three circuit breakers, and a bridge rectifier. The bridge rectifier provides +28 volts dc for the coils. The circuit breakers are each rated at 2.5 amps. The breakers are numbered 1, 2, and 3 as viewed from the rear of the machine and left to right.
- Breaker # 1 protects power to the game board and the backbox lamps.
- Breaker # 2 protects the playfield lights.
- Breaker # 3 protects the bridge rectifier and the 28 volt solenoids.
The bridge rectifier is also inside the transformer box. Notice the 2 bar chimebox inside the backbox. Wico manufactured the chimebox assembly themselves. Also visible is the game board in the upper right corner.
4.3 Solenoid Problems
Wico did something different than other manufacturers: the solenoid driver transistors for playfield coils were mounted right next to the unit it drives! Each unit (sling, pop bumper, and even the flippers) has a terminal strip next to it with the individual resistors, capacitors, and transistors for driving that particular unit attached to it. Each terminal strip has a 1k resistor, a 2.2k resistor, a .22 uf capacitor and an SE9300 or TIP102 driver transistor on it.
Solenoid power for the playfield coils originates at the power box connector P5. Power for the chimebox coils originates at the power box connector P6. If all coils are dead, check for +28 volts DC at either connectors P5 or P6 on the power box at pins 1 (+28v) and 2 (ground). If no voltage present at those terminals, either the bridge rectifier is bad or the circuit breaker #3 is tripped/bad. If the voltage is low (less than 20 volts) then replace the bridge rectifier.
4.4 Lamp Problems
If backbox lights (and game board power) are out, check circuit breaker #1 on the power box. If the playfield lamps are out, check circuit breaker #2 on the power box assembly. All lamps are either #44 or #47 miniature lamps (6 volts).
4.5 Switch Problems
4.6 Display Problems
4.7 Sound Problems
Big Top used a 2 bar chimebox for sounds. It did not use electronic sounds nor did it have a speaker. The driver transistors for the chime coils are on the game board.
4.8 Flipper Problems
Big Top uses classic Stern Generation 1 flipper assemblies with a Wico coil and a 20 ohm 25 watt resistor attached to drop power to the coil.
- Complete Flipper Unit, Stern # B-195-L-1 (left) or B-195-R-1 (right)
- Base Plate, Stern # 1B-309-L (left) or 1B-309-R (right)
- Coil Stop Bracket, Stern # A-186
- End-of-Stroke Switch, Stern # SW-294-BL (left) or SW-294-BR (right)
- Return Spring, Stern # 5a-151
- Plunger and Link Assembly, Stern # A-197 (with fiber link) superceeded by A-633 (with plastic link)
- Flipper Arm (pawl) assembly, Stern # A-191-L (left) or A-191-R (right)
- Plastic Flipper Bushing, Stern # 4A-111-W-1
4.9 Pop Bumper Problems
The coil bracket is a Williams # 04-10888 or B-7417.
4.10 Slingshot Problems
- Main mounting "L" Bracket, Stern # 1A-269
- Coil Stop Bracket, Stern # A-232
- Front Coil Bracket, Stern # 1A-271
- Return Spring, Stern # 5A-151
- Plunger and Link assembly, Stern # A-145
4.11 Outhole Ball Lift Problems
The ball return assembly appears to be either a kickback unit or a knocker unit from a classic Stern machine.