Williams WPC


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1 Introduction

See here for The WPC System Boardset and History

2 Technical Info

Motorola 68B09E, running at 2Mhz. It is an 8-bit/16-bit CPU with a 64KB address space. Bank switching is required to address more than 64KB. The game ROM size varies from 128KB to 1MB, depending on the game. 8KB of battery backed RAM is available.

For more information, see The FreeWPC Manual

3 Games

WPC (Alphanumeric)

WPC (Dot Matrix)

Gilligan's Island
Terminator 2: Judgement Day
Hurricane
Party Zone

WPC (Fliptronics)

The Addams Family / Addams Family Gold
The Getaway: High Speed II
Black Rose
Fish Tales
Doctor Who
Creature from the Black Lagoon
White Water
Bram Stoker's Dracula
Twilight Zone

WPC (DCS)

Indiana Jones: The Pinball Adventure
Judge Dredd
Star Trek: The Next Generation
Popeye Saves The Earth
Demolition Man

WPC-S (Security)

World Cup Soccer
The Flintstones
Corvette
Red & Ted Road Show
The Shadow
Dirty Harry
Theatre of Magic
No Fear: Dangerous Sports
Indianapolis 500
Johnny Mneumonic
Jack*Bot
WHO Dunnit

WPC-95

Congo
Attack from Mars
Safecracker
Tales of the Arabian Nights
Scared Stiff
Junk Yard
NBA Fastbreak
Medieval Madness
Cirqus Voltaire
No Good Gofers
The Championship Pub
Monster Bash
Cactus Canyon

4 Problems and Fixes

5 Game Specific Problems and Fixes

5.1 Doctor Who

The time expander in Doctor Who can be very problematic - the opto boards crack and prevent the mushroom targets on the 2nd level of the time expander from working properly. Often the boards can be fixed with jumper wires and resoldering, and there are aftermarket boards available to replace both. Additionally, the plastic carrier the optos are attached too can warp, preventing the warped section from working. Finally, there is a cardboard shield attached to the carrier that prevents stray light leakage from affecting the optos (most notably during the Davros rounds). If it is missing usually you cannot complete the round as the light from the lock lamps prevents the optos from turning off.

5.2 Indiana Jones

The front right switch on the path of adventure gets hit underneath by ball hits. This shorts the wires/diode/switch lugs. This switch is on the same row or column as the ball jam opto. This is the last opto a ball goes by going up to the shooter lane. So if you are getting extra balls kicked up to the shooter lane, that front right switch is a good place to start. LTG :)

5.3 Medieval Madness

Draw Bridge is acting up

Check the pivot points, they get peened by ball hits and can distort and bind. A bit of work to take apart, they can be flattened or filed to make a smooth pivot point again. LTG :)

Troll carriages. Gravity can loosen the collar from the cage, and cause binding on the up or down movement. You can re-peen it with a cold chisel. Or braze it. The collar is much thicker than the cage so welding won't work, you'd melt the cage.

A common problem is a broken wire on the troll head target. Easiest is to take the whole carriage out of game. Remove the bolt holding it to plunger, unplug the connector. Lift up and wiggle out, lean to one side so long part clears playfield hole. Remove nut on plastic piece and remove. Remove troll target. Cut cable tie. Resolder wire good. Check both wires and diode. Reassemble. Put on new cable tie. Install back into game. LTG :)

5.4 The Shadow

Fast shots to the lower phurba ramp diverted to the right sometimes get stuck because of the switch wireform hanging the ball up. One way to fix this is to get a replacement microswitch with a long wire actuator, and bend it so the activation occurs much later down the wireform ramp, as shown in this photo: Media:shadowswitch.jpg

5.5 Star Trek TNG

There is a thin wire running from the 8 driver board (right side of backbox) to the single drop target reset coil on the playfield. Make sure this wire is present and secure, as coils will lock on if not. Replace this wire with a thicker variant to help prevent it breaking from vibration and stress.

You might remove the three wires from the lug ( purple wire/green stripe, the thin one looks more lavender) and solder to a single wire and solder the single wire to the coil lug. that way if it ever breaks off from vibration, the three stay together and don't knock out a transistor on the small driver board and lock on a subway coil.

Missing ball or Extra Multi-Ball: A common problem is broken wires on the trough optical board(s), especially the large 270 ohm resistors. One way to test is to put the machine in switch edge test mode and bang on the playfield just above the flippers to see if any switch edges register. They should not. Replacement boards are available with shock mounts or you can alter your own boards by drilling out the holes and adding grommets. <<LINK TO CONVERSION INSTRUCTIONS NEEDED.>>

5.6 The Getaway High Speed 2

Super Charger not accelerating well and then blows fuse 103. All 3 magnets pulse no matter which opto is interrupted

The ball did not accelerate well and was blowing fuse 103 on the Solenoid Driver Board after a few revolutions. I worked on it for a while then put the project on the shelf for a few months after getting advice from lots of helpful folks on RGP. I posted results of further testing early last week. I noted that all three magnets seemed to pulse no matter which opto was opened.

Clive Jones pointed out the problem could be with one of the 2 CMOS chips on the Accelerator board or a LM339 on that board. By checking the optos in switch test I verified the optos all worked fine and there were not multiple openings when I opened any of them with my finger. This ruled out a LM339 So I replaced the CMOS chips U2 (4011) and U3 (4071) (shotgun repair I know :)) *maybe someone could chime in on how to test those CMOS chips. I put the board in and a new fuse and man that ball started flying around the super charger. Man was I relieved. Now the average speed according to the Supercharger time test is in the low 80s.

5.7 White Water

Ball hangs on "lip" of reproduction ramp between Spine Chiller ramp exit and upper playfield

The reproduction ramps from Pinball Inc are excellent. Some Spine Chiller ramps finished manufacture with an almost undetectable "lip" at the exit point of the ramp. Prior to installation, use an Exacto knife or similar to slice that lip off.

Ball sits in "dimple" under "lock-to-upper-playfield" VUK

After thousands of landings from the VUK onto the same upper playfield spot, the playfield becomes dimpled. The ball will sit in that dimple until shaken loose or until another ball emerges from the VUK (as in multi-ball). A "Cliffy" protector will solve this problem quite elegantly. [1]

Ball spins backwards after being launched up the "lock-to-upper-playfield" VUK

Sometimes, the ball will "backspin" after being ejected from the upper VUK, slowing gameplay. Install one (perhaps two) rubber post rings (or rubber grommets) as pictured here: [2]

5.8 Twilight Zone

The mini playfield connectors. The opto and magnet connectors are the same size. Match up wires not just connector size. If mixed up the optos will blow out. LTG :)

Have seen the ASIC not seating properly. Can cause funny DMD problems (even after ribbon cables have been changed). To remove the chip correctly you will need a PLCC extractor tool, available at any good PC supply shop. You also need a cleaner. You can use isopropyl alcohol and a Q-Tip (or new paint brush) to very carefully clean the 'legs' and pop it back in place.

Follow this procedure to 'spring' the legs slightly so the problem won't occur again: GPE ASIC Repair Thanks, Ed. Good to know for a last resort when you've looked everywhere else.

For more information see Twilight Zone Clock and Twilight Zone Eddy Boards

6 Repair Logs

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

Williams WPC

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