Sentinel / Wonder Wizard

1 Introduction

Sentinel, Inc. which was a division of Magnavox Consumer Electronics Company (North American Philips, or simply NAP) manufactured four models of home version pinball machines in 1977 and 1978. They used the Wonder Wizard trademark on the machines. The trademark was registered by General Home Products Corp., a division of Magnavox Consumer Electronics Company. The trademark (registration number 1066305) was active from August 5, 1976 to October 18, 1983 and is now cancelled.

2 Games

• Flying Aces (1977) Model number PH7730WA01 with a flying theme.
• Demolition Derby (1977) Model number PH7730WA02 with a car crashing theme.
• C.B. Charlie (1978) Model number PH7730WA03 with a trucker/ CB radio theme.
• Star Explorer (1978) Model number PH7730WA05 with an outer space theme.
• Star Explorer (1978) Model number PH7730WA15 same as above, but made by Philips Electronics for Canadian distribution.

CB Charlie

Demolition Derby

CB Charlie and Demolition Derby home model pinball machines.

Flying Aces

Star Explorer

Flying Aces and Star Explorer home model pinball machines.

All of the machines had the same cabinets and playfield layout, but with different artwork.

3 Technical Info

Sentinel, Inc. machines are covered by the now expired patents 4203602 (the ball is used as an electrical switch between two "hot" contacts) and 4109916 (one coil mechanically operating two devices). This was unique in that it lowered manufacturing costs by not having to use as many coil assemblies.

Backbox dimensions: 17" high by 22" wide by 9" deep.

Main cabinet dimensions: 46" long by 20.5" wide by 6.5" deep.

Assembled machine weight is 68 pounds.

Motherboard: # 702605-1

Display board: # 702604-1

Solenoid driver board: # 702603-1

Audio board: # 702602-1

Owner's Manual which applies to all four Sentinel machines.

File:Sentinel Owners Manual.pdf

4 Problems and Solutions

4.1 Power Problems

There are two power supply bridge rectifiers on the motherboard in the backbox. BR401 and BR402 are both type RC204-1 (2 amps @ 400 volts). It is strongly suggested to upgrade these to 8 amps @ 400 volts. Radio Shack bridge rectifier # 276-1181 will be fine to use.

Power transformer, breakers, and boardset

Sentinel 702605 motherboard

Motherboard showing the two bridge rectifiers as well as the master volume control.

4.2 Solenoid Problems

On solenoid driver board # 702603-1 are five driver transistors and 5 smaller pre-driver transistors. Q301, Q303, Q305, Q307, and Q309 are the solenoid driver transistors and are "house marked" as RCA 393. These are in reality type 2N6099 and you can substitute the common TIP 102 transistor such as used in other commercial pinball machines. Q302, Q304, Q306, Q308, and Q310 are the pre-drivers and are "house marked" as 1482. These are in reality type 2N4401 or NTE 123AP transistors.

Sentinel 702603 solenoid driver board

The solenoid driver board showing the 2N6099 driver transistors (the large ones) and the 2N4401 pre-driver transistors (the small black ones).

4.5 Display Problems

The digital display on 702604 display board develops bad solder joints on the pins of the display itself. Be sure to check the soldering of those pins if display problems are being experienced.

Sentinel 702604 display board

Look closely at the pins of the display for bad solder joints on the foil side of the board.

4.6 Sound Problems

The volume control pot is soldered to the 702605 motherboard in the backbox. The shaft of the control gets banged around alot which causes the terminals of the control to develop bad solder joints on the motherboard.

Sentinel 702602 audio board

There are several pots on the audio board. Don't play with them. Be sure to clean the foil fingers of the edge connector.

4.7 Flipper Problems

These are old classic Stern Generation 1 flipper assemblies operating on 24 to 28 volts DC. Some parts are reproduced by Pinball Life. The 3" flipper bats have an offset pivot point. If you put standard 3" bats on, they will be way too close and the ball cannot go past. These machines should have had 2" Gottlieb flat top flipper bats.

4.8 Pop Bumper Problems

These are classic Stern/Chicago Coin pop bumper assemblies with the coil operating on 24 to 28 volts DC. There is no skirt or bumper return spring since the electrical circuit is made by the ball contacting the metal ring on the playfield and the rod & ring.

4.9 Slingshot Problems

These are old Stern/Chicago Coin slingshot assemblies with the coil operating on 24 to 28 volts DC. The electrical circuit is made by the ball contacting the metal strip on the playfield in front of the slingshot and the metal spring around the plastic posts. There is no rubber ring around the slingshot because of this.

4.10 Eject Hole Problems

If the coil or it's diode are shorted, the circuit breaker will trip.