Miscellaneous Pinball Fix-it Hints
Ok guys ... here's a bunch of hints I've decided to ramble on
Realize the majority of my experience is Williams/Bally games
(Whirlwind to the present), so that's what I'm restricting myself
- Make sure the little piece of rubber that hits the EOS
switch doesn't wear through -- the metal post will cut a
hole in the end of the EOS switch, causing the flipper to
stick. Replace the whole crank ... they don't cost much.
- Replace your flipper sleeves, coil stops, and cranks
frequently -- they're less expensive than new coils.
- Make sure the paper wrapper stays on the flipper (and any
other) coil as this will help keep the wires from getting
- Use the spacing guage in the spare parts bag to set the
spacing between the crank and the bottom of the bushing
... this will prevent binding or excessive looseness
(both of which will wear out the crank and sleeve).
- Replace the coil if a new sleeve won't slide easily into
it -- this means the coil has expanded from heat and will
bind a crank sliding through it.
Flipper circuits (WPC games)
- Check the optos on the flipper cabinet switches and U4/U6
on the fliptronic II board (LM339s) as a weak or leaking
LM339 (quad voltage comparator) can cause a perfectly
maintained flipper mechanism to behave like it hasn't
seen a wrench in five years. Optos can get dusty, so make
sure they're fairly dust free ... but don't use Freon
(canned air) as it's cold enough to damage the LED
and photo transistor.
- Weak flippers that are mechanically fine ... replace the
TIP36C darlington, it's TIP102 driver, and the 2N4403
predriver for that flipper. A weak TIP36C may leak
slightly causing both warm coils and weak flips.
- Non-functional switch ... check the diode. Replace it.
With a 1N4004.
- Check the column driver (ULN-2803) on the CPU board.
- Obviously, you should also check the wiring first ...
make darn sure the right wires are connected ...
cross connected columns and rows can cause all kinds of
- If it's a microswitch, they do go bad too ... listen
carefully for the "click" when the switch
Lamps, flashers, and coils
- If wires and diodes and all are all ok (and the coil
isn't burnt out) you likely blew a driver transistor ...
check the manual for location and replace it. It'll be on
the power driver board or (in the case of the wide body
games) possibly on an auxiliary driver board.
Care and feeding
- All pivoting points should be oiled, with the exception
of flippers. This means the hinged points on ball
launchers, trough poppers, slingshots, and similar
mechanisms. Use 3-in-1 light machine oil. Never, ever,
oil the plunger of a coil. The graphite given off by the
plunger sliding through the coil sleeve is sufficient
lubrication. Anything added will cause the graphite to
clump and become a gummy, gooey mess.
- Check your flipper and other coils every now and then ...
replace any worn sleeves and wipe down the shafts.
Replace any coils that are binding.
- Clean your playfield *weekly*. Dirt and grime buildup are
the #1 cause of eventual failure of electrical and
mechanical parts. Keeping the playfield clean will keep
the dirt out of switches, off lamps, etc ...
- Rotate your flipper rubbers when the tips get worn and
use rubber cleaner (RC-88 from Wildcat) on the playfield
rubbers every time you clean the playfield.
- Don't forget to clean the balls too, or simply replace
them. New balls are only $1.25 each or so. Scuffed balls
will tear your playfield to pieces.
- Be sure to level the game left-right (use a carpenter's
level on the upper and lower parts of the playfield) as
well as a 6.5 degree slope. Best way to set the slope is
to visit your distrubutor and purchase one of those nifty
slope bubbles Williams puts on their games ...
- Diamondplate finishes are essentially sealed in plastic.
I use Novus plastic polish #2. Novus #2 is also good on
mylar. Spread it on and buff it in like car wax. Let dry,
and buff off. Change cloth frequently to get clean cloth
on the playfield. Whatever you do, don't use
Wildcat 125 on a Diamondplate (or other hardcoat)
playfield. It will damage the acrylic plastic hardcoat,
ruining the playfield.
CP-100 is okay, but be forewarned that it will strip
mylar off a playfield as easily and efficiently as it
strips off the dirt and grime !
- I also use a soft brush to brush all the bits of novus
and cloth pieces off the playfield -- just brush it down
the drain at the bottom of the playfield. It'll drop down
to the bottom of the cabinet for easy cleanup.
- Check your light bulbs for cleaning ... under-playfield
bulbs will get very dirty from solenoid dust, etc. Wipe
'em clean and see how much brighter your inlays get!
- not much here ... but note that slingshot switchs should
be spaced 1/16" apart.
- Common light bulbs are 555 and 44, as well as 89 and 906
Twilight Zone use #86 lamps in the clock.
- All switch, lamp, and coil diodes are 1N4004,
coil/flashlamp drivers are TIP102's, hi-power coils are
TIP102/TIP36C pairs. Each uses a 2N5401 predriver.
- Flipper power drivers are TIP102/TIP36C pairs, flipper
holding drivers are TIP102's. Each uses a 2N4403
- Never ever ever get RC-88 rubber cleaner on playfields
... it'll eat through Diamondplate and strip paint right
off. Never use any spray or cleaner on cracked paint --
it'll seep under and the paint will flake off. Wildcat
#125 will cloud clear plastic ramps.
- Novus cleaner can also be used to clean playfield
plastics (undersides too), plastic ramps, backglass art,
Anything I forgot?
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