Atari Pinball Problems/Solutions.
01/20/06. By cfh@provide.net
This information applies to all Atari pinball games.
This document is a "work in progress", and is not complete.
Game List.
- Atarians, 11/76, widebody, 1 player.
- Time 2000, 06/77, widebody.
- Airborne Avenger, 09/77, widebody, 350 made.
- Middle Earth, 02/78, widebody.
- Space Riders, 09/78, widebody.
- Superman, 03/79, widebody.
- Hercules, 05/79, largest pinball machine ever made, last full production pinball machine made by Atari.
- Road Runner, 1979, widebody, 2 player, only two made.
- Monza, 1980, cocktail pinball, 4 player, only one made.
- Neutron Star, 1981, only one made.
- 4X4, 1983, only two made.
Documentation.
ROM Software.
Batteries.
Only Superman and Hercules (basically the last two full
production pinball machines made by Atari) used batteries: three "AA" style.
Boot Up Procedure.
Immediately after power up,
the Score Display should be showing all "888888"
and the PLAYER UP indications (1st up, 2nd, up, etc.)
lights one at a time, in numerical sequence.
All 8's should be showing in the Credit Display and the Match/Ball Display too.
The displays are all operating properly if every display
segments lights up at least once. But if one or more segments
remain dark, the display may have a problem
Check on +90 and -90 Volts Power Supply Voltages.
Remove the playfield glass, then remove the lower arch panel.
WARNING: Use caution whenever AC voltage is applied to the game.
High voltage is present on the bare terminals of the score panel's
edge connector J21, and at various other points on both circuit boards.
Here's some steps:
- Defeat the Interlock Safety Switch by pulling all the way out
on the switch's spring-loaded plunger.
- Turn the game on.
- Connect a voltmeter across the following capacitors shown
in the diagram, and check for the readings listed below:
- On the Match/Credit Display PCB place meter's ground
(black) lead on "plus" side of C2; other red lead placed on "plus" side
of C1. This should show +90 volts DC. Now put the red DMM lean
on the "minus" side of C2. This should show -90 volts DC.
- On Score Panel PCB, place ground lead on "plus" side of C2;
other lead on "plus" side of C1 gives +90 volts reading,
and on "minus" side of C2 gives -90 volts reading.
If one or more readings are low (or at zero volts),
check each PCB separately as follows. Disconnect J19 and
re-measure the voltages on the Score Display PCB. If the
voltages are OK, then some portion of the circuitry on the
Match/Credit Display PCB is pulling down the supply voltages.
If the voltages are still incorrect, reconnect J19,
disconnect J17, and re-measure voltages on the Match/Credit
display PCB. If voltages are OK, then some portion of the
circuitry on the Score Display PCB is pulling down the supply voltages.
If voltages remained incorrect while each board was checked
separately, leave J17 and J19 both disconnected. Then check
the +90 volt and -90 volt outputs on the Auxiliary PCB
(where the high voltage power supply circuitry is located).
These 90 volt supply voltages must both be present on each
display PCB before the displays can light up.
If all voltage readings on the display PCBs are within
5% of the correct values, then go on to the next portion of
the procedure.
Score Panel Removal and Visual Checks
After the +90 volt and -90 volt supply voltages have
been verified, the next troubleshooting step on the score
panel will be to remove it from connector J21.
- Turn off power to the game.
- Remove the metal clips holding the score panel onto the bracket arms of J21.
- Using your right hand, grasp the right edge of the score panel.
Carefully lift it up approximately 1/4-inch, and then pull
it straight out and remove it completely.
- Examine the positions of the terminal pins on J21.
Tips of the pins should be aligned in the same plane,
and not be bent down or up. If not bent out of alignment,
all pins can then make contact with the score panel's
terminal strips when the panel is plugged in.
- Next examine the condition of the terminal strips
on the score panel. If the surfaces of the strips are
corroded, replace them.
Replacement of Score Panel
After the visual checks have been made on the J21 terminal
pins and on the score panel, the original score panel can be
put back, or else a new score panel can be substituted in its
place. Carefully observe the following procedure when replacing
the score panel.
Using both hands, grasp the right-hand edge of the panel
and carefully slide it fully into connector J21, perfectly
aligned. Then lower the edge down until the entire panel
rests in the bracket arms. You will note some free space
on each side between the panel and the brackets. At the
factory a rubbery substance called RTV was placed between
the bracket arms and the score panel. This substance provides
a cushion between the glass panel and the metal arms, and
positions the panel so that connector J21's terminal pins
line up exactly with the panel's terminal strips. Be sure
that they are aligned correctly.
Solenoid Drives.
Atari uses 2N6044 transistors as the solenoid drivers.
The 2N6044 can be replaced with a TIP122 or TIP102,
which is a common NPN style driver transistor used
by most of the pinball makers during this era. The driving
chip for the TIP transistors is a less common 7407
through a 1N914 (or 1N4148) diode.
Switch Matrix.
Switch matrix is largely handled by a slew of 74145 chips
to a 9301 chip. If solenoid voltage shorted to the switch
matrix, one of the 74145 chips would be suspected first.
Internals of a Atari Hercules pinball.
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