6) Do you hear ticking? Since
the early 'battery powered EM'
days, most prewar pinball
machines
have a main power switch on a 3 to 5 minute mechanical
'windup' timer to conserve
electricity. This timer usually looks somewhat like
a bicycle's
handelbar bell, and is usually
mounted under
the playfield near the front
of the machine. This timer is
wound and started by
pushing in the coin slide. The switch contacts
inside the timer keep the machine powered
up
until the
time runs out, and then turns off the power to the machine. In this
photo from a Genco
Step Up, the wires coming from the timer are the
power
wires to the main AC power relay's
coil.
If you don't hear ticking when
you put a
nickel in the machine and push in the coin slide,
the
timer is probably
stuck. It will need to be cleaned and oiled soon, but 'just for now'
you
could take a jumper wire and jumper across the
switch for
testing
purposes
only. You will
need to clean and repair the
timer as soon as
possible to properly play the
game.
7) Check
your tilt and shutter reset switches! Every prewar EM
pinball
machine has a shutter assembly of some kind
under the playfield to catch the already played
balls,
like the small brown one shown at the bottom of the underside of the
Airway of 1937's playfield in the photo at left.
Unfortunately, due to the small size of the photo at left, you don't
see these
three shutter reset switches below. One of these
resets the 'tilt' relay, another resets the scoring stepper motor in
the
backbox to 'zero', and the third one resets the bank
of latching relays found in the bottom of the Airway's main cabinet
that
operates the bumper and backbox lights. Notice the
generally bad condition of these switches and the gray tarnish on the
switch contacts themselves. If the Airway was played
with these switches in this condition, none of the functions operated
by
these three switches would work at all. The
switches in the photos at left and right are NO (normally open)
switches that
close when they are touched, so the
leaves of these switches should be very carefully bent
straight again and set so there
is
a gap roughly a little less than the thickness of
a business card
between the contact points when they are not operating.
Then, a little DeOxit on a flat burnishing
stick will remove the gray oxidation from the points. The
switch in the middle photo
doesn't look too badly aligned, so cleaning this
switch the same way as you cleaned the others should
work. When you are
finished cleaning these switches, test them with
your meter as you move the shutter back and
forth so you are sure that
they are working properly.
The tilt
relay (usually found mounted to one of the walls of the backbox) turns
off the main power relay when the machine is
'tilted'. The brass
plumb bob usually found in the inside corner of the
playfield cabinet is one part of an electrical
switch, and the ring around the outside of the
bob
is the other half.
If the plumb bob touches the outside ring, the tilt latching relay
turns on, turning off
the main machine power and turning on
a TILT light usually located
somewhere on the backglass. To unlatch the TILT relay and reset the
machine, the tilt shutter reset switch must be
operated by operating the shutter (shown above). To
temporarily turn this function off, just
remove the power wire from the ring part of the tilt,
or
simply take out the tilt bob. Also, check and clean
the 'slam tilt' switches commonly found located on the
floor and sides of the machine,
because sometimes metal objects can
fall
into these and short them out. On some machines, you can unplug the
tilt switches from the
tilt relay
so it doesn't turn on. If the tilt relay is humming,
the TILT light won't turn on and the machine won't turn
on, check the TILT light bulb in the
backbox and check the tilt relay
switch stack (if
you have one) to see if it is hanging up. Also, check the shutter reset
switch and slam switches
to see if any of the switches are stuck.
8) Reset
your scoring stepper!
The main score counting mechanism for our
machines is the stepper motor, like the one
from my Bally Airway of
1937 shown here.
The left photo shows the two rows of switching
contacts on the insulating
plate, the long arm
that
moves when a solenoid (the red one
shown in the
photo at right) pulls in, and most
important... the 'zero switch' shown in the
upper left corner of the photo at left. This switch
must be closed for your game to completely
reset itself at the beginning of every game.
Now, for some weird reason my poor Airway was stored
for a very long time after being
unplugged in the middle of a game, long enough so
the stepper motor's main
shaft became
stuck in place at the highest
scoring position. When I tried to reset the stepper manually by
moving
the black solenoid coil's plunger to unlatch the ratchet, the
stepper still wouldn't move
to zero. Also, the gray tarnish and oxidation on the
rotary switch's
brass contacts would never
let the machine operate properly. So, I cleaned the
entire mechanism
with compressed air,
and cleaned and oiled the mainshaft and both of the
solenoids'
ratchet pivot assemblies until
the mechanism would advance and reset properly by
hand. Then I
cleaned and checked the
'zero switch', and used a plain steel flat brush in
my Dremel tool
(shown at right) to clean the
rotary switch's contacts until they were clean
again. After that, I
wiped the contacts with a
cotton swab dipped in DeOxit to remove any unseen
dirt. When I was
finally done, moving the
red solenoid's plunger worked the ratchet, moving
the toothed wheel
and advancing the switch.
This also wound up the mainspring under the long
arm. When I
moved the black solenoid's
plunger, the locking
tooth pulled away from the toothed wheel, releasing the wheel. The
mainspring would unwind, moving the long arm from
the top of the switch in the photo at upper left to
the zero
position at the bottom of the switch. Since the long and short arms are
attached to
the same axle, when
the long arm is at the lowest set of contacts then the short arm closes
the 'zero switch' so the game can begin. Also,
while you're at it, if your machine has any electric
motors inside for backbox animation, score motors, etc. a small drop of oil at each
bearing
will do wonders for them too. If you do have a score
motor in your game, don't forget to clean the motor's switches with
your flat burnishing
stick and DeOxit too.
And after all of
these are completed, the moment of truth...
9) Add
some power... Plug in your Variac
into the nearest AC power outlet, turn the Variac's selector knob
to zero, plug in the machine's
power cord into the Variac and turn it on. Turn up
the Variac to 50
volts or so. You may see some slightly glowing lightbulbs (probably the
TILT light in the backbox), but you probably won't
hear or see anything depending on how the relays and steppers in the
machine are set,
and
that is OK. Most of these machines are designed to turn
completely
off when their timers do, and completely reset all of the relays and
other
switches when
a new game is started. If you smell any weird burning smells, blow any
fuses
in the machine or in the room, or hear very loud
buzzing coming from the machine, turn off the
power immediately! Either one of the relays is burned, or a switch is
either shorted or stuck on.
You will need to fix this before you go any further.
If you hear or see nothing, this may not be a bad sign... just find
where the coin slide pushes
onto the shutter to
reset the machine at the beginning of a game, slowly push the shutter
all the way toward the backbox until it stops, and then
pull the shutter all the way back until it stops
again. This action usually was
used to totally reset the machine, so now the main backglass
lighting should come on dimly, and the playfield
bumper bulbs
(on ESCO and certain other makes) should also turn on. You should also
hear
various soft buzzes from some of the different
relays and
solenoids, since there isn't enough voltage applied to the machine to
make them
activate fully. If there is no arcing or sparking
'welding'
sounds, and no burning smells, turn up the Variac's voltage knob very
slowly to 110
VAC, while listening for any arcing, smelling for
any burning,
and looking for any completely dead lighting or any sparking. As you
approach
110VAC, any buzzing relays should activate
and fall silent, and you should have a silent machine, except for the
ticking of the timer mentioned
in hint #5 above. If you still have any hot or
buzzing relays or
solenoids,
see if you can find them and mark them in some way, since the
switches
that operate these will have to be repaired before you can continue.
If
everything seems OK, turn off the Variac, close the playfield,
close the coin door, turn the Variac back on and set
it to 110 VAC so the game has full power again, put a nickel in the
coin slide, and work
the coin slide like you are starting a game. This
should now completely reset the machine, since
there
is now enough voltage applied to the
machine to make the relays and motors operate
properly. If you're very lucky,
the backbox lights will come on, the machine will fully reset, and
you
will then be able to repair the rest of the machine. If you aren't
lucky, you have more work to do...
----------------------------------------------------------------------------------------------------------------------------------------------------------
By now, you're probably wondering why I'm suggesting
why you should even do these things to your machine.
These machines are so ruggedly
built and technologically simple that the number 1 cause of death for
these machines seems not to be
actual defective parts but plain and simple
neglect. Think about it... the ESCO Idaho in the
photo at the top of this page may be in very good
condition today indeed, but it was still built in
1944, which makes it 65
years old. This machine probably had an expected service life of only
roughly 3 to 5 years, so this would mean that even
if this machine was kept in
perfect storage conditions all this time, it still was unplayed for
many years. Electrical parts simply do not improve
with age. If EM pinballs like
this Idaho aren't played frequently, then the switching contacts
on
relays and switches as well as terminal
connections on cables and other parts may tarnish and
oxidise. This oxidation is a good electrical
insulator, and in many cases once it forms it will
make important parts of
your pinball operate sluggishly or not at all. Once a pinball machine
ever ceased to play properly, it usually had a very
short future ahead
of it. Even if a repairman willing to repair a machine and
actually had the
skill and parts to do it properly could somehow be
found, the cost to repair it
would be incredible. This is one of the reasons why so many
great early
EM pinballs are extinct today.
I hope this page's information helps
you repair your own vintage pinball machine, and playing it gives you
pleasure
for many years to come.
One more thing... I want to say Thank You to the late Russ
Jensen, who was
not only one of the hobby's
greatest
historians with many articles to
his credit in many magazines, but the author of the book
pictured at left
- "Russ Jensen's Pinball Troubleshooting Guide". This book is 49 pages
of solid
information on
repairing early pinball machines, 'pitch and bat' games, and other
electromechanical
arcade machines.
Unfortunately, this book is long out of print, so you may have to
search for it on the
Internet. I
suggest that if you manage to ever find a copy of this book, purchase
it - it is as close to
being an actual
'textbook' on this subject as you will ever find.
Thank you,
ken
Prewar Pinball Yahoo! Group
Copyright 2009 Prewar PInball Yahoo! Group -
All Rights Reserved
2) Replace
the power cord! The power cords of these
machines have
all without exception gotten very
3) Check
the fuses and fuseholders! Many times, the
game's fuses have
simply
blown or the fuseholders have
4)
Clean
your cable plugs! I learned
about this
trick from my wife's
1950 Bally
5) Check
your coin door wiring!
Many later games (like the Idaho's door assembly at left) have