Atari Repair

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1 Introduction

Atari, widely known for their extensive video game library, also produced pinball machines for a short time during the late 1970's. In many ways, Atari went against the norm in both their design and style of their machines. All of the produced Atari machines, other than the massive Hercules, were widebody designs. Early machines featured score displays mounted in the apron area, with circuit boards in the lower cabinet.

After Hercules, in 1979, Atari ended their involvement in pinball, instead opting to focus on the video game and home console markets.

2 Games

• 4x4 (widebody, prototype)
• Airborne Avenger (widebody)
• Hercules (oversized, Gen2)
• Middle Earth (widebody)
• Monza (cocktail, prototype)
• Neutron Star (prototype)
• Pipeline (never produced)
• Road Runner (widebody, prototype, Gen3)
• Space Riders (widebody)
• Superman (widebody, Gen2)
• The Atarians (widebody)
• Time 2000 (widebody)
• Triangle (never produced)

3 Design Variations and Atari quirks

Atari pinball system can be effectively divided into two distinct generations, which will be referred to as Gen1 and Gen2. The vast majority of machines produced were manufactured utilizing the Gen1 board set. Only Superman and Hercules utilized the Gen2 system. Road Runner, of which only two machines were made, utilized a Gen3 design that was never put into production.

The two styles are easily distinguished both in their layout and locations. Gen1 boards incorporate all of their components into a single large sized circuit board, which is mounted in the lower cabinet below the playfield. Gen2 boards were split into two separate boards, a CPU board and an I/O board, which are connected via a 40 pin cable.

Note that while using the same basic board, Gen1 boards are not drop-in interchangeable. Boards were assembled according to the machines they were going to be installed into, and not all components were installed on the board. You will need to inspect a donor board to see which solenoid circuits are actually installed, and you may need to install additional circuits in order to activate all solenoids.

Atari took a very different approach to their circuit designs than other manufacturers of the same era. Rather than use an 8x8 matrix design for switches and lamps, Atari machines have discreet connectors and wiring for each lamp and switch. This results in a large number of wiring connectors and wires, as each switch and each lamp, generally, has its own dedicated wire and connection. Though in some cases multiple switches may be daisy chained together, if they perform the same actions, such as Switch 20 on Superman machines.

Another interesting feature is that the insert lamps do not turn on and off like other manufacturers. Instead of being normally turned "off", lamps are kept turned on, but in a dim state. When a lamp would be turned "on", it's switched from dim to bright. This was done intentionally, in order to extend bulb life, by reducing the stresses incurred in the filament when switching on and off. However, this also means that Atari machines are not compatible with LED lighting for the inserts, as they would always be turned on.

4 Technical Info

Superman coils (all are 50 volts DC):

Atari # A007030-01 is used for the pop bumpers, slingshots, outhole, eject hole, and drop target reset. Approximate dc resistance is 6 ohms and it has a 1N4001 diode soldered across the terminals. Coil has 1/4" quick connect terminals (no soldering needed). The coil sleeve is Atari # 006791-01. I believe Bally # AN-26-1200 will work for a substitute.

Atari # A020470-01 (25/790) is the flipper coil. Has two diodes installed. The high current pull-in winding is 4.5 ohms dc resistance. The total resistance of the pull-in and hold windings is approximately 150 ohms. Coil has 1/4" quick connect terminals so no soldering is needed. Uses Atari coil sleeve # 006791-01.

Marco Specialties stocks the Atari coils.

5 Problems and Fixes

5.1 Power Driver Issues

Pertains to Atari "Superman" pinball:

All playfield coils except for the flippers do not work. Chip B4/5 (CD4013) is the solenoid enable select. Replacing it restored all playfield coils to normal operation.

Solenoid driver transistors are type 2N6041.

Lamp driver transistors are type MPS-A06.

5.2 MPU Issues

Pertains to Atari "Superman" pinball.

Clocking: Atari utilized a unique clocking system that utilized two independent clock channels, a main clock and an audio clock. To further complicate the issue, the main clock switches back and forth between two different speeds, depending on which portions of the boardset the CPU chip is accessing. When reading from the ROM chips, the main clock speed is generally seen as 1mhz. However, for most RAM and I/O circuits the main clock will slow to .67mhz due to the slower components being accessed. The audio clock runs at a fixed speed of 2mhz. (To be updated with clock testing procedures.)

Switch problems: many switches not recognized or operating one switch triggers several other switchs. Replace chips H7 (74LS244), E6 (7407), and D6 (7407).

Battery holder corrosion: There is a 3 AA battery holder made of aluminum that will corrode over time causing loss of battery backed data like replay scores and bookkeeping. Drill out the four rivets and unsolder the two terminals to remove the old battery holder. A new, seperate, 3 AA battery holder with wire leads can be mounted near the board. The wire leads will solder directly to the + and - terminals on the MPU board. You do not need to install an additional blocking diode, as there is already one in place on the circuit board.

5.3 Power Supply Issues

Pertains to Atari "Superman" pinball:

Fuses:

F1 Machine main power fuse, 5 amp slow blow, located on metal box on bottom of cabinet. F2 Service Outlet fuse, 2 amp slow blow, located on metal box on bottom of cabinet. F3 To BR1 & C1 (50 volts dc to coils), 15 amp slow blow, located in backbox. F4 To BR2 (+7 volts circuit), 15 amp slow blow, located in backbox. F5 To BR3 & C2 (+12 volts circuit), 7 amp slow blow, located in backbox. F6 For 6 volts AC general illumination circuit, 15 amp slow blow, located in backbox. Note: some machines may be incorrectly labeled as a 10 amp slow blow fuse. Fuseholder may tend to burn up. F7 Center tap of 6 volt circuit, 1 amp slow blow, located in backbox.

All three bridge rectifiers are type MDA3501.

5.4 Display Driver Board

Possibly doesn't apply to some, can't think of an example.

6 Repair Logs

Did you do a repair? Log it here as a possible solution for others.