Demolition Man

From PinWiki
Revision as of 06:36, 18 May 2016 by Jimpal (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
Manufacturer System Year Model Produced
Williams WPC-DCS Sound 1994 50028 7,019

1 Game-Specific Issues

Overview picture of the Demolition Man Cryo Claw, in the "home" position.


The Demo Man Cryo-Claw can sometimes be problematic.

At game boot, proper behavior is for the elevator to run through a cycle, then the cryo claw will move all the way to the right (into the position where it would pick a ball from the elevator) and then move all the way to the left "home" position (see picture).

The motor must be removed to get to the PCB which signals the MPU that the claw is either at the left or the right rotation limit. To remove the motor:

  1. Disconnect the motor power connector from the bi-directional motor drive board below the playfield
  2. Disconnect the power and ground connector for the cryo claw magnet (also below the playfield)
  3. Loosen the two screws that hold the gray plastic edge trim to the backboard and remove it.
  4. Remove the two screws that hold the metallic plastic "claw" cover.
  5. Remove the 5 position lamp and claw selection assembly by removing three screws attached to long standoffs.
  6. You may have to remove the two long standoffs on the left.
  7. Loosen the two screws that secure the gray motor cover. Once these are removed, you can wiggle the motor cover out, exposing the actual motor and gearbox.
  8. Remove the .100 pin connector at the opto board.
  9. Remove the 4 screws that secure the motor assembly to the back board.

You should now be able to remove the entire motor assembly. Easy, eh?

A-16986, The Demolition Man Cryo-Claw motor "end of throw" PCB.


The cryo-claw motor identifies when it is at the "end of throw" via two cams on the motor disc and two optos on the opto board. The two optos are shown on the board at the left (Williams part number A-16986). Potential problems are fractured solder joints on the optos or the .100 right angle headers. Failed 470 ohm 1/2 watt resistors can be an issue too, due to the amount of heat that they dissipate.

The height of the cryo claw can be adjusted with these two set screws in the back of the claw arm assembly.


The height of the cryo claw can be adjusted so that the ball falls from the magnet from a height sufficient to overcome the rollover microswitch arms. Use a 3/32 hex head wrench to loosen the two set screws (pictured left). Slide the arm to the best height, and tighten the set screws. There is no need to worry about angular precision as the set screws engage a flat side of the motor shaft.

1.1 Trough Error Message

Generic trough error message


If the opto receivers cannot see the transmitters in the trough for one reason or another, the game will display the message to the left. Reasons for the opto receivers not seeing the transmitters are spelled out within the message. In other words, the message is actually not ambiguous like most other messages.
This message may very well be specific to Demolition Man and no other WPC-DCS games.

Return to Williams WPC page.