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.

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.

Sentinel 702605 motherboard

Motherboard showing the two bridge rectifiers.

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).

4.7 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.

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.