IMPORTANT: Before you Start!
Table of Contents
2. Before Turning the Game On:
3h. When things don't work: Infrared Optic Switches
Several different optos used in Williams games. The "U" shaped
optos are used for Fliptronics flippers, Twilight Zone clocks, etc.
These consist of a transmitter and receiver in one package. The stand-up
optos are two parts: the green board opto stand-up is the transmitter,
and the blue board opto stand-up is the receiver. The transmitter
LED is larger and protrudes further from its case. The single diode
shown is a replacement LED transmitter for the stand-up optos, and
for opto boards used in ball troughs, etc.
Optos are used on fliptronics
Williams uses optos for lots of applications. WPC Fliptronics flipper buttons are opto activated. Many clear ramps have opto ball sensors. Many pre-1990 Williams drop targets use optos (they stopped using them there because the leads would break from vibration, and the optos would fall off). All WPC-DCS (1993) and later games use optos to sense balls in the ball trough.
Two parts to a opto switch.
Because the transmitter is always on and producing light (and hence heat), the transmitter is the part that fails 98% of the time in a opto switch.
Optos can get dusty from the "black dust" inside a game. To clean an opto, use a Q-tip dipped in glass cleaner. Wipe the opto with the Windex-wet Q-tip, then dry the opto with a clean, dry Q-tip. Do NOT use canned air to blow optos clean! The air in these cans is too cold and can damage an opto.
Testing Opto Switches.
If an opto switch doesn't work, first check that your +12 volts is working. If you have blown the +12 volt fuse, there will be no power to the optos, and they won't work.
If there is +12 volts going to the opto, there is a good chance the transmitter has failed. To test the receiver, first put the game into the "switch edge" test. Then block the opto transmitter with a piece of tape. Now shine a penlight flash light into the receiver. The switch should "close". When you remove the light, the switch should "open". If the receiver is working properely, there's a good chance the transmitter has burned out.
If you have +12 volts in your game (Hint: do other optos work?), and the opto switch doesn't register in the diagnostic test, your opto transmitter is probably burnt. The receiver side of an opto switch almost never dies. That's because it only senses light, and doesn't produce light. The transmitter will be the offending unit 98% of the time. But there is a good way to test the transmitter side of an opto switch.
assembly. The LED's can be seen lit in this photo, but you won't
be so lucky with the naked eye. That's why this Infrared Sensor
card is so handy.
Optos on Newer WPC games.
The Opto Receiver and Transmitter Tests Good, now what?
WPC Fliptronics Flipper Optos.
Use your infrared sensor card to determine if the opto is working on the flipper board. If you suspect a problem with this opto (and don't have a infrared sensor card), you can swap the left and right flipper opto boards, and see if the problem moves to the opposite flipper. Note: you must have both flipper opto boards plugged in for this test to work! Opto board power is jumped through the left opto board. Both opto boards must be plugged in for the right one to work!
If indeed one of the flipper optos is bad, and your game only has two flippers, you can reverse the two optos on the bad flipper opto board. One of the optos will be unused since the game only has two flippers, instead of four. Mark the bad opto, and its position on the opto board. Then unsolder both optos, and throw the bad one away. Then re-solder the good opto into the marked position on the flipper opto board.
Weak Flippers and Bad LM339's on the Fliptronics Board.
If there is a marginal flipper switch reading, this causes the high powered side of the flipper to rapidly oscillate between on and off. The holding side of the flipper coil never engages. This problem will cause the flipper coil to get very hot in a short time.
The industry part number for the "U" shaped optos is QVE11233, with a standard sensitivity of .0110. Unfortunately, Williams requires a higher sensitivity opto for their applications. This means the cheap $1 optos from most electronic supply houses won't work, as their sensitivity rating isn't high enough. If you are shopping for these "U" optos, keep this in mind. You should be looking for part number QVE11233.0086, where .0086 is the increased sensitivity rating.
3i. When things don't work: Eddy Sensors (electronic ball sensors)
used on Theatre of Magic. Note the potentiometer and
LED. The connector on the left goes to the actual
under-the-playfiled mounted "sensor" (see pictures
below) that tell this board there is a ball above it.
That is all that is required to adjust an eddy sensor. To test the sensor, put the game into WPC diagnostic's first switch test. Then move a pinball over the playfield area where the eddy sensor is located. The switch should activate on display.
Twilight Zone Eddy's.
used on the outlanes of many games.
Right: another type of eddy sensor that senses the ball. This sensor is
used in Theatre of Magic and covers a wider area.
3j. When things don't work: Ball Trough Problems (random multi-ball)
Starting in 1993 with Indiana Jones, a new ball trough design was used that instead relied on gravity to feed the ball into the trough. This saved one coil (the outhole coil was no longer needed). The new design also used opto switches instead of mechanical switches. This allowed one ball trough design to be used in all Williams games, regardless of the number of balls used in the game. The ball trough could now comfortably hold from one to seven balls (depending on the game).
the balls. Note the large blue resistors used on the top board. Often
these resistors can vibrate and break. This will give the opto board
false ball senses or no ball senses.
When the opto ball trough was first used on Indiana Jones, William bolted the opto boards right to the side of the trough. The vibrations from the trough often caused the leads on the large blue resistors and the infra-red LED's on the opto transmitter board to break. This would cause the game to start random multi-ball at just about anytime during the game. Often the game would never end (because the trough would not reconize when all the balls had drained).
To fix this problem, Williams redesigned the attachment points for the two opto boards. Instead of being bolted directly to the trough, the mounting holes on the opto boards were enlarged (and one hole moved). Then special rubber gromets where inserted into the holes. Lastly, 1/4" metal tubes where inserted through the rubber gromets. When the opto board bolts where tightened down, they tightened on the metal tubes. This allowed the opto boards to "float" on the rubber gromet, reducing vibration considerably.
Ball Trough Upgrade Kit.
being worn in the ball trough. These cause the balls to hang and not roll
the length of the ball trough.
Another problem with the new ball trough design is "divots". As the pinballs fall into the ball trough from the playfield, they eventually dig divots into the metal. This can cause the balls to hang and not roll the length of the ball trough and down to the shooter lane upkicker coil. All sorts of weird game problems can occur from this. The most common is trying to start a game by pressing the start button, and the game responds with "pinballs missing", or a game that doesn't end when the ball drains.
To fix this, you can often use a Dremel tool and grind the divots out of the metal. If this doesn't work, you can order a new ball trough, part number A-16809-2. This newer design of the ball trough should last longer and divot less.
More Random Multiball: the Ball Trough Optic Resistors.
3k. When things don't work: Dot Matrix/AlphaNumeric Score Displays
WPC Alpha Numeric Score Display Problems.
some characters in the display (on the right side).
The unfortunate part about dot matrix displays (DMD) is they wear out. Time will eventually kill these, and the display will "outgas" and fail. Because of the high voltage involved with score displays, the anode and/or cathode inside the diplay glass breaks down. This results in the "outgassing" of impurities that eventually change the internal gas properties, so the display can't glow (the gas must be very pure for the display to work). Often the gaps that don't light up at power-on will gradually come on as the display warms up. This happens because as the existing gas warms up, it expands. A new display will solve this problem, and is easy to get and replace (a 5 minute job). These do cost a bit of money though at about $115 each (complete). There is no way to fix an old "outgassed" display.
But the really bad news about DMD's that are failing is how they die. When a DMD starts to get blurry or displays gaps, the power requirements for the display dramatically increases. This stresses the dot matrix controller board. If the display is not replaced, the controller board can fail too. Sometimes the controller board burns beyond repair.
The moral to this story is to replace a marginally bad DMD with a new display as soon as possible. Don't postpone the inevitable. You can get a new DMD from Competitive Products Corp (800-562-7283) or Pinball Resource (914-473-7114). The whole assembly is about $115.
Buy an entire DMD display glass and board, or just a new Glass?
Diagnosing Other Problems.
Make sure to check fuses F601 and F602 (all WPC games). F601 is used for +62 volts, and F602 is used for -113, -125 volts. On WPC-S and before, these are 3/8 amp fast-blo 1.25" fuses. On WPC-95, these are T0.315 amp 5x20mm fuses.
controller board. Use the "key" pin for reference to figure out which is pin 1
and pin 8.
If the fuses are good on the dot matrix controller board (or audio/visual board for WPC-95), you should next check the power at the DMD itself. Voltages used are +62, +12, +5, -113 and -125. Check these voltages at the dot matrix display, or at connector J604 on the controller board. The pin out is:
Display and fuses good, but still missing or low voltages.
Also you will need to check resistor values. They should be within 10% of spec:
Generally either Q1/Q3 or Q6 will go bad. If either of these fail, both should be replaced(make sure you use white heat sink compound when replacing these, and make sure you have them screwed tightly to their heat sinks). The MJE at Q7 comes after Q6, so it usually survives. Also the smaller switching transistors that are connected to Q1/Q3 and Q6 should be replaced (MPSD02 and MPSD52). Finally the zener diodes 1N4759 (62 volts) should also be replaced. The diode 1N4742 (12 volts, D6, D8 on WPC-S and prior and D3, D5 on WPC-95) generally do not go bad. On WPC-S and prior, check the 120 ohm 1/2 watt resistors at R4, R5 and 47k ohms 1/2 watt at R3, R6, R12, R13. Also check the 4.7 ohms 5 watt and 1.8k ohms, 5 watt resistors. Replace any resistors that are out of tolerence or that appear burnt. Always mount the resistors slightly above the board to allow air flow below them.
Cloudy Dot Matrix Display.
Wavy Hum-bar in the Dot Matrix Display.
Crystallized Solder Joints.
Replacing Q2/Q10 and Q4/Q5 on the Dot Matrix Controller board.
3L. When things don't work: Power-On LED's and Sound Beeps
A simple diagnostic LED (Light Emitting Diode) flash pattern exists on all generations of WPC CPU boards. These flashes can signify a problem and what might be causing the trouble. They can be seen immediately when powering on the game. LED's exist on both the CPU and Driver boards, but only the CPU board's LED have a diagnostic flash pattern. On WPC-S and earlier CPU boards, the LED's are labeled D19 to D21. On the driver board and all WPC-95 boards, they are labeled "LEDx" (with "x" being the LED number).
CPU Flash Codes WPC-S and Prior.
Sound Board Error Beeps pre WPC-DCS (WPC alpha-numeric, WPC dot-matrix and WPC fliptronics.
Sound Board Error Beeps WPC-DCS and WPC-S.
Driver Board Flash Codes WPC-S and Prior.
WPC-95 CPU Flash Codes.
WPC-95 Audio/Video LED.
WPC-95 Driver Board LED's.
3m. When things don't work: "Factory Settings Restored" Error (Battery Problems)
Most often, this error occurs because the three "AA" batteries on the CPU board have died. These batteries should be replaced every year with good quality alkaline batteries (batteries are cheap, battery damage is expensive). The three batteries must keep at least +4 volts of power to the U8 RAM chip for it to remember. When power goes below +4 volts, memory reset can occur (and you get the "Factory Settings Restored" error message).
If after replacing the batteries, you still get a "Factory Setting Restored" error, suspect the battery holder. Use your DMM and check the battery voltage at the CPU board. With the game off, put your DMM on DC volts and put the black lead on ground (the grounding strap or on one of the screws holding the CPU board in place). Put the red lead on each of the CPU board's POSITIVE battery terminal SOLDER POINTS. Test each of the three batteries' positive leads individually. You should get about 1.5, 3.0, or 4.5 volts at each battery (note the batteries are additive and the first battery in the chain will give you 1.5 volts, and the last battery will give you 4.5 volts). If you don't these positive voltages, suspect damaged battery holder terminals. These corrode quite often if new batteries aren't installed religiously. Replace the battery holder and re-test to ensure proper repair.
Is power getting to the U8 RAM chip?
Next test for voltage at the CPU U8 RAM chip. With the game off, you should get about 4.3 volts DC at pins 26, 27 or 28 of chip U8. If you don't, the battery voltage is not getting to the U8 RAM chip, and the game will boot up with the "Factory Settings Restored" error. Note pin 28 of the 28 pin U8 chip is in the same position as pin 1 of the chip, but on the opposite row of pins. Pin 1 is designated with an impressed "dot" right on the top of the chip.
You can still have problems even if you installed new batteries and all the voltages check out. If your game is still giving "Factory Setting Restored" or "Set Time and Date" errors, you may have a bad CPU U8 RAM chip. But make sure you double check that battery holder. Even minor corrosion can cause this problem. The voltages may all check out, but the corrosion may be enough to limit CURRENT, and cause this problem. The U8 RAM chip is a 6264-L or 2064 RAM chip.
There is an internal time clock that keeps the time and date for the WPC system. Within the game's adjustments, you can turn the clock display on, so it shows the time and date on the dot matrix display. On Twilight Zone, this internal time clock is used during attack mode to set the playfield clock. If you notice the WPC time clock running slow (losing time), or the game just won't remember the time (boot up error of "Set Time and Date"), the batteries are getting weak and need replaced. If you still have this problem with new batteries, suspect the battery holder's terminals. They may be corroded enough to cause resistance, and lower the voltage at CPU chip U8.
If your game is working, and it's time to replace the batteries, follow this procedure:
If you install new batteries with the game turned on, the machine will not forget the old option settings or bookkeeping totals.
3n. When things don't work: Lightning Strikes
The MOV is the green disc soldered across the
3o. When things don't work: Sound Problems.
Volume up FULL and Can't turn it Down.
Lots of Static.
3p. When things don't work: Test Report & The Diagnostic Dot.
Most test reports refer to switches that are tagged as defective. Often this is not the case. If a switch hasn't be used in 30 games, it will be listed as bad. But it could be the switch is working, yet positioned in a place that it just doesn't get activated much during game play.
If you do get a test report about a possibly defective switch, go to the "switch edge" test and manually activate the switch. This will indicate if the switch is working. If it does work, this will reset the 30 game counter for this switch and the switch will not be reported in the test report.
Prototype ROM Software and Bad Switches.
The Diagnostic Credit Dot.
3q. When things don't work: Fixing a Dead or non-booting CPU board.
It doesn't happen often on WPC games. You have power (+5 and +12 volts) getting to the CPU board. The +5 LED (lower of the three) is on, as it should be. But the middle diagnostic LED is not flashing constantly (indicating the CPU is dead). And the blanking LED (the top one) is doing nothing (no flashes when the game is turned on). You have a dead CPU.
WPC-S and Prior CPU Flash Codes .
WPC-95 CPU Flash Codes.
Dead CPU Step One: Remove the Ribbon Cables.
After everything is removed but connector J210, turn the game on. If the CPU board boots correctly, the lower LED (+5 volts) should be on, the middle LED (diagnostics) should be blinking continually, and the top LED (blanking) should be off. If this is the case, turn the game off and replace the ribbon cables, one at a time, and turn the game back on. When the CPU doesn't boot, you have found the connector (and hence the board) that is dragging the CPU down.
Move to the Work Bench.
and ground are clearly marked on these.
Right: a computer power supply. You'll have to check the
power supply lines to get the right voltages on these.
But 99% of the time, red = +5 volts, yellow = +12 volts,
and black = ground. Double check them with your DMM.
J210, the green aligator clip goes to ground, the red to +5 volts, and
the yellow to +12 volts.
With the CPU on the workbench and issolated from the game, you can test the board much easier.
Re-seat the U9 WPC chip.
Bad socket at U9.
3r. When things don't work: Miscellaneous Oddities.
The Clock won't keep Time.
Answer: Both legs of crystal X1 were soldered to the same spot! It looks like it came from the factory that way. After removing the crystal and putting both legs in the correct locations, the time is tracking correctly.
The 32.768 KHz crystal is very common and used in everything from wrist watches to computers to anything that keeps time. The reason for that particular frequency is 2 to the 15th power equals 32,768. The frequency is very easy to divide by two, fifteen times, using flip-flops or some other form of divider network. This nets a one second time increment. Since your crystal was shorted, the oscillator was free running at a RC-determined frequency that undoubtedly drifted with temperature and miniscule voltage changes, hence the accumulated errors.
I can't enter my high score initials on Funhouse.
Answer: there are two optocouplers on the power driver board at U7 and U8 that are numbered 4N25. If these go bad, they will prevent the flippers from moving through the high score initials. Since this game does not have fliptronic flippers, these optocouplers don't effect the flippers themselves. If this was a fliptronics game, the flippers wouldn't have worked either.
The flippers and dot matrix display died while playing a game.
Answer: the +12 volts has died, probably from a bad fuse at F116, or maybe a bad BR5 bridge. Some dot matrix power is derived from the +12 volts, and the +12 volts also powers the optos (hence the auto ball launching problem and no flippers). If the +12 volts is good, unplug the fliptronics and sound board ribbon cable, leaving just the dot matrix display plugged in to the ribbon cable. Now see if the display clears up and you can see the error report.
Strange Error Message.
Answer: Every flipper opto board has two optos. One is wired to the lower and the other to the upper flipper switch inputs. This is true even on games with just lower flippers. If the flipper opto board has a dirty opto, you can get this error, even if your game doesn't have the flipper reported in the error message. Clean your flipper opto board optos with a Qtip. Replace the opto if the problem doesn't resolve.
Dot Matrix Display Got Blurry.
Answer: the ASIC chip on the CPU board was not making good contact to its socket. The ASIC chip is the large square chip on the CPU board. After removing the chip and cleaning all of its pins, and reseating the chip in the socket, the problem went away. Another thing to try is reseating the ribbon cables in their sockets.
4a. Finishing Up: Rebuilding Flippers
Flippers get weak because they have moving parts that get substantial use. When they wear, the mechanisms get play (slop) in these moving parts. Instead of the flipper coil transmitting all its energy in propelling the ball, some energy is absorbed by the sloppy mechanisms. Rebuilding the flippers removes this slop, and will dramatically increase the strength and feel of your flippers.
How Flippers Work.
To simplify how the two sides of a flipper coil work, it's best to examine the non-fliptronics version. In this case, when the flipper is energized and at full extension, the normally closed EOS switch opens. This removes the high powered side of the coil from the circuit. The low powered side of the flipper coil is always in the circuit, but is essentially ignored when the high powered side is in the circuit. This happens because the current takes the easiest path to ground (the low resistance, high power side of the coil). The low power high resistance side of the flipper coil won't get hot if the player holds the flipper button in.
Pre-fliptronics games have a high voltage, normally closed end-of-stroke (EOS) switch. But Fliptronics flippers are basically an electronic (instead of mechanical) version of the above explained non-fliptronics flippers. The main difference is fliptronics flippers have EOS switches that are low voltage, normally open switches (instead of high voltage, normally closed as used on non-fliptronics flippers).
and the style of return spring used. The EOS switch is a high voltage, Tungsten
contact, normally closed switch. This flipper coil is installed incorrectly; can you
Right: A freshly rebuilt Fliptronics WPC flipper. There is no capacitor, and a different
return spring. The EOS switch is a low voltage, gold contact, normally open switch. This
flipper coil is installed correctly.
Answer to the above trivia question ("what's wrong with the left picture's flipper coil?"):
The problem shown on the left is the flipper coil is installed upside down!. The wire terminals that the flipper coil wires connect should be as far away from the coil stop as possible. The coil stop is where most flipper vibration originates. The coil plunger slams into the coil stop, causing vibration. This vibration will eventually break the coil wires off of the coil wire lugs. To minimize this, the coil is mounted so the wire lugs are further away from the coil stop. The coil picture on the right is mounted correctly.
When the player presses the flipper button, the high-powered side of the flipper coil is activated and fully extends the flipper. Then the end-of-stroke (EOS) switch is opened, and removes the high-powered side of the coil from the circuit. As the flipper reaches it's end-of-stoke, the flipper pawl opens the high voltage, normally CLOSED switch. The electricity now only passes through the low powered side of the flipper coil. The use of the low powered, high resistance side of the flipper coil consumes less power. This allows the player to hold in the flipper button without burning the flipper coil. If the high-powered side of the coil was activated alone for more than a few seconds by itself, the coil would get hot, smoke, smell, and burn.
Non-Fliptronic EOS switches use a 2.2 mfd 250 volt capacitor (part number 5045-12095-00). This minimizes the high voltage electrical arc between the contacts of the EOS switch. The EOS switches on these games do need periodic maintainence. Since they are high voltage switches, there is some electrical arcing. This will cause the switch contacts to pit and burn, and cause some resistance. As the resistance increases, more arcing occurs (which causes even more resistance). Eventually, bad EOS switches will make the flippers very weak. They must be filed clean with a small point file periodically. The switch contacts are made of Tungsten.
Fliptronics WPC Game Flippers.
The EOS switch is now a low voltage, normally OPEN switch. As the flipper pawl reaches its end of stroke, it now closes the EOS switch.
When the player presses the flipper button, the CPU turns on the high powered side of the flipper coil. When the EOS switch is sensed closed, the high powered hold side of the coil is turned off. If for some reason the EOS never closes, the CPU turns off the high powered side of the coil after a short period of time (a few milliseconds). The low-powered hold side of the coil is powered for as long as the player holds the flipper button.
Computer control of the flipper coil via the Fliptronics board provides an extra level of reliability to the game. The computer now controls this. The EOS switch is monitored, and if the computer sees a problem, the operator is notified via a diagnostic message. But if the operator chooses to ignore this, the game will still function as designed. Also, since the EOS switch is now a low-voltage, gold plated contact device, it requires no big maintanence schedule.
Flipper Coil Numbers and Strength.
Flipper Rebuild Kits.
Rebuilding Fliptronics and Non-Fliptronics Flippers.
Right: The coil stop. Notice the mushroomed head on the top example. Below that is a re-worked coil stop (using a file). It is recommended replacing the coil stop rather than re-working it.
Measuring the coil stop with a dial caliper.
First, use your allen wrench and remove the two 10-32 x 3/8" bolts that hold the coil stop in place. This will release the coil from the assembly. Move the coil to the side for now.
Examine the coil stop. Often, the coil stop will have a "mushroomed" head. This happens from the coil plunger slamming into the coil stop. If this is the case, replace the coil stop. In a pinch, you can re-work the coil stop and file the mushroomed head flat and bevel the edge. The problem with this is plunger travel length increases. If excessive, the plunger link will now slam into the top coil bracket, destroying it. Also the increase in plunger travel can cause the flipper pawl to hang on the EOS switch (leaving the flipper in the up position). A new coil stop is .440 inches thick. If your coil stop, after filing, is less than .425 inches thick, you should replace it. Less than .425, and you'll have problems with the flipper pawl hanging on the EOS switch, especially on fliptronics flippers.
assembly removed. The flipper shaft can
be seen extending thru the playfield,
and thru the nylon flipper bushing.
On Fliptronics flippers, remove the one side of the return spring from the flipper pawl. Then using your allen wrench and an open wrench, loosen (but don't remove) the bolt that clamps the pawl assembly to the flipper shaft. From the playfield side, turn and pull the flipper while holding the pawl assembly until the flipper can be pulled from the playfield. The pawl assembly can then be removed from under the playfield.
Worn Coil Bracket?
The flipper bushing is a nylon part that the flipper shaft passes through. Unless it is cracked, or the flipper was very weak, or the game has more than 30,000 plays, it may not be necessary to replace this part. It's pretty easy to tell if it needs replacing. With the flipper pawl removed from the flipper shaft, wiggle the flipper on the playfields, side to side. There should be some play, but not excessive play.
Right: Note the plunger tip has mushroomed, and there is considerable plunger pitting.
The flipper pawl assembly can now be rebuilt (if you buy a whole new flipper pawl assembly with a new plunger/link for about $10, skip this section). Remove the allen bolt that holds the flipper plunger/link to the pawl. The plunger/link can now be removed (you may need to use a screwdriver to spread the pawl assembly slightly to release the plunger/link).
Top: New style, fatter and more substantial flipper link.
Replace the flipper plunger and link. A new plunger/link can be bought for $1.50. (rebuilding the plunger is hardly worth it. Spend the $1.50 and get a new plunger/link. If rebuilding the plunger/link is your only option, here's what to do: grind and bevel the plunger tip to remove the mushroom. Using a 1/8" metal punch, remove the roll pin that holds the link in place. Install a new link, and hammer the roll pin back in place. Make sure the new link moves freely.)
freshly installed (white) pawl heat shrink tubing and allen bolt.
The flipper pawl's job is to activate the EOS switch at the flippers' end of stroke. This metal pawl tab is factory coated with heat shrink tubing to prevent wear to the EOS switch. When the coating is worn, metal-to-metal contact (pawl to EOS switch) occurs. This will shred the EOS switch blade. When the EOS switch blade frays, it will hang-up on the flipper pawl. This will cause the flipper to stick in the up position (regardless of the condition of the return spring).
The heat shrink tubing also provides insulation between the metal flipper pawl and the EOS switch. This is especially important on non-Fliptronics games (as the EOS switch is a high voltage switch). Worn or missing heat shrink tubing on these games can cause all sorts of strange game behavior.
New pawl heat shrink tubing should always be installed when rebuilding the flippers. Cut the old tubing off using a razor blade. Cut a 1/2" length of new 1/4" heat shrink tubing. Push it over the pawl, and use a heat gun or hair drier to shrink the tubing in place. Trim with a razor blade as needed.
coil. Note the use of the white plastic
flipper "tool" to get the spacing correct.
Often, operators will replace a flipper coil with the wrong type. This happens quite often. You should verify in the manual that your particular game has the correct flipper coil installed.
Re-installing the Flipper Pawl Assembly and Flipper Coil.
Put a new coil sleeve in the flipper coil. If you can't get the old coil sleeve out of the coil, replace the entire coil (it has been heat damaged otherwise the coil sleeve would easliy slide out). The coil sleeve should be installed from the non-terminal end of the coil, and extend through the coil at the terminal end about 1/8".
Williams changed flipper return spring styles in 1992. Before, there was a cone-shaped flipper return spring that went over the flipper plunger. The problem with this set up was it chewed up the flipper link, and often the spring just got weak and broke from the constant contact with the flipper link.
To combat this problem, Williams made two changes when they went to Fliptronics flippers. First they changed the style of flipper link to be thicker, and have a more rounded contact point. Second they stopped using a plunger style return spring. The return spring was moved outside of the plunger, where it takes less abuse and doesn't chew up the flipper link.
Left: Here the flipper plunger spring has gone soft, and
won't return the flipper back. Note how the spring is biting into
the flipper link (new style flipper links help prevent this).
Tightening the Flipper Pawl Assembly.
Cleaning and Adjusting the EOS Switch.
On non-fliptronics games, clean the EOS switch contacts with a small file. There should be no pitting in the contacts when done. The EOS switch is a normally closed switch. So adjust the non-fliptronics EOS switch so it opens about 1/8" at the end of the flipper's stroke.
On fliptronics games, make sure the EOS switch doesn't hang on the flipper pawl when the flipper is fully extended. Clean the EOS switch by running a business card through the closed contacts once or twice. The EOS switch is a normally open switch. So adjust the fliptronics EOS switch so the contacts close when the flipper is at its end of stroke.
4b. Finishing Up: New Coil Sleeves
4c. Finishing Up: Protecting Slingshot Plastics
4d. Finishing Up: Cleaning and Waxing the Playfield
There are a number of products available for cleaning the playfield. Millwax comes to mind. (Personally, I would avoid this product. Millwax isn't even really a wax. It's a cleaner with extremly small amounts of wax and lots of solvents to keep the cleaner/wax in an easy-to-apply liquid form. It's false protection; you're not waxing your playfield, you're only cleaning it with Millwax. Also Millwax contains petroleum distillates, which are probably harmful). Stay away from Wildcat products. They react with plastic and can crack mylar and yellow plastic ramps.
Personally I like Novus#2 plastic polish for cleaning playfields. It works great, and leaves a great shine. It contains no harmful solvents. It's very gentle, yet cleans fast and well. I buy it at my local grocery store, but you can also get it through most pinball retailers. It is also the product recommended by Williams for your playfield!
If your playfield is Diamondplated, using a wax after cleaning is optional. All Williams playfields were Diamondplated starting with Terminator2. Prior to that, the playfield will say "protected by Diamondplate" in one of the outlanes if it is indeed Diamondplated. Diamondplate is basically a polyurathane top coating originally used to protect hardwood floors.
Also a scratched ball can slow and damage the playfield. Replace the ball if it's not shiney like a mirror. They are only about $1.25 each. Throw the old balls away.
4e. Finishing Up: Playfield Rubber
I would recommend not using black rubber on your games, unless it was designed for it. It looks bad, is much harder, and hence has different (less!) bounce. Black rubber is now pretty much standard equipment on most Williams games after about 1995. For an operator, black rubber gives a distinct advantage: it doesn't show dirt! This creates an illusion. But in reality, black rubber creates black dust, so you have to clean the playfield and parts more often. For the hobbiest, I would recommend using white rubber instead. It gives a brighter look to your game. And on newer games that don't have much rubber, white rubber can give more ball bounce.
Some games were designed, and looked better, with black rubber. Scared Stiff and Attack from Mars were two such games. Later new games (like Circus Voiltaire, 1997) were going to be designated for white rubber by the designer, but got black rubber installed at the factory.
Clean rubber has amazing bounce properties. Dirty rubber has seriously reduced bounce. The more bounce, the more fun your game will be. If you want to try and clean your old (only slightly dirty) rubber, you can use WAX. Johnson's Paste Wax, Meguires Carnauba Wax, or even Novus#2 plastic cleaner works great on lightly soiled rubber. Just remove the rubber and wax it with a CLEAN rag, and wipe off the excess. Wax will keep your rubber supple and UV protected. You don't even have to remove the rubber if it's not too dirty. For dirtier rubber, try alcohol. Use a clean rag and wipe the rubber down. If flipper rubbers are wearing out quickly, reverse it (turn it inside out), and re-use it.