Hi Shawn
its a fun pin - great, ipdb http://www.ipdb.org/machine.cgi?id=1072 has the schematics and the manual: http://mirror2.ipdb.org/files/1072/Williams_1976_Grand_Prix_Manual.pdf look-up page-12 (ori-10) --- Mech. Panel means bottom-board in the Cabinet, Insert means "mounted in the Backbox more or less near the Score-Drums, Playfield means underneathside of playfield.
So when I write "Left Bonus Relay": You can look-up and read "mounted on the playfield".

Lets only look (for the moment) at ONE-Player-Games. You can start a game and get the first ball out - You can play and make some points - You loose the ball and the Bonus-Ladder is stepped down (OK, not nice: No points given) --- Have the playfield up and simulate such an first ball --- question: Does the "Left-Bonus-Relay" pull-in ? (Or: The Right Bonus-Relay ?) - The Score-Motor runs and the Bonus-Ladder is stepped down --- question: DOES the Left/Right-Bonus-Relay QUIT pulling ?

Another great page in the manual is page-6 (ori-4) - the Start-up cycle --- maybe we have to have a look at (?) Anyway, Ball is lost, Bonus is stepped down --- question: DOES the Left/Right-Bonus-Relay QUIT pulling ?
Locate the Outhole-Relay --- when the "stepping down the bonus-ladder" is done and the pin stands still --- AND THE Left/Right-Bonus-Relay HAS quit pulling: Use a wooden stick or wear rubber gloves and manually actuate the Outhole-Relay --- what happens ?
(((Maybe the pin comes into an endless loop - then simply togle-off the main power switch))) Greetings Rolf

Hi Shawn
You make points but the Ball-Index-Relay does faulty not pull-in. It should pull-in and stay pulling all the time until the ball is lost , Bonus-Ladder has counted down --- THEN the Relay must let go - as the new ball is kicked out.

Try: Manually make some points - manually activate the Ball-Index-Relay --- question: Does the Relay STAYS pulling ? (or does it let go when You stop manually activating ?). Greetings Rolf

Hi Shawn
the Grand-Prix has a feature I do not really like (it makes the pin more complicated): EVERY new ball given starts with the Bonus-Ladders "one bonus given".
Your post-4 "manually activating the Outhole-Relay ... both Bonus-RELAYS ??? want to STEP DOWN ???" --- What should happen: "manually activating ... both Bonus-UNITS want and actually do step-UP one position (the "not loved by me feature"). Please write again about the situation.

The first ball is given to You - You make some points - You add some bonus --- You manually activate the Ball-Index-Relay - it stays pulling - You loose the ball - the bonus-ladder is stepped down --- question: Do You NOW get the bonus points ? - You then manually activate the Outhole-Relay --- does the pin kicks-out the SECOND ball ? --- Means, question: Is this (close to) playing a game ? Greetings Rolf

Hi Shawn
thanks for the corrigenda and "other things written".
The Ball-Index-Relay is loud buzzing - can You live with it for a while ? The interesting question is: After some 10, 20, 30, ... 60 seconds: Does the Coil on the relay gets HOT ? If "Yes": Do not let it get hot, write about - we have a look at. IF "No": I would like to accept the annoyance and proceed.

The following is not trouble-shooting - is not fixing --- it is for "to make the work-around You now must do - make this a bit easyer". Look in the ipdb-manual at page-25 (ori-23), Ball-Index-Relay, bottom-most switch - Switch-A - the so-called "Self-Hold-Switch on the relay" - a short wire runs from one side of the Coil to this switch.
Try: Take an rather small screwdriver and hold the tip of the screwdriver at this switch "touching BOTH blades at the same time --- not touching other stuff" - then take away the screw-driver --- the Ball-Index-Relay should pull-in and stay pulling --- question: Does it ?
Locate "alike" Switch-A on the Outhole-Relay and try the screwdriver-trick --- the Outhole-Relay should pull-in and stay pulling --- question: Does it ?

With the tip of the screw-driver You made a little short - You manually / electrically closed the Self-Hold-Switch. Think of "clip-on two Jumper-Wires at the solder-lugs of the two blades" --- run the other ends of the two Jumper-Wires through the open Coin-Door into the open --- at the time You want the relay to pull-in: You tip the two Jumper-Wires (gator-clips) together - relay pulls-in.
Want to get fancy (?): Mount an doorbell-type pushbutton at the ends of the Jumper-Wires and simply press the pushbutton to make the relay pull-in.

Troubleshooting: Look at the wheel of a Bonus-Unit when it is stepped down --- a rod on the wheel comes closer and closer to an three-bladed Make-and-Brake-Switch --- question - when stepping from One-Bonus down to Zero-Bonus: Is this switch MOVED (middle blade moves) ?
OF COURSE: Either the real ball is laying in the Outhole or YOU have Your finger parked there CLOSING the switch below / underneathside of the playfield. Greetings Rolf

Hi Shawn
in the snippet from the ipdb-schematics see (red lines) - when You bang a TILT (Pendulum Tilt): The Ball-Index-Relay must pull-in --- question: In Your pin ?

The green lines show the "normal" activating --- can You use the ipdb-manual and look-up the switches (my brown question marks) - then look them up in Your pin - wires soldered-on ? contact-points clean ? actuating properly ?

The fault might be elsewhere --- in the connecting wires / Jones-Plugs. Just have a look at the mentioned switches - do not spend hours on them. Greetings Rolf

P.S.: In Switzerland it is getting "eleven at night" --- I go to sleep - till tomorrow.

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Hi Shawn
it is a hobby - we work on the pin when we have time and lust.
The pendulum tilt should work - but its a minor problem - later.
The Outhole-Relay does only pull when You close the switch - not so good but You manually can have the switch closed until the ball is kicked over - later.

My goal always is "to fix 'easy to fix stuff' and make an 'work-around on more difficult stuff' " so the owner can play a bit (and then he wants to fix the more complicated stuff).
The biggest problem by now is "no points given when the bonus-ladder is stepped down at end of a ball".

See here http://www.ipdb.org/showpic.pl?id=1072&picno=35554 on top of the playfield the Eject-Hole worth 5000 points --- question: (When the ball rolls into) Do You get the 5000 points ?
Here http://www.ipdb.org/showpic.pl?id=1072&picno=35542 above / between the flipper-bats: The Number-1-Light --- can You "play good" and make it lit ? Otherwise: Actuate the No-1-Star-Relay.
Then loose the ball --- question: Are You rewarded with Bonus-TEN-Thousands ?

See the JPG
--- when You are rewarded with Bonus-TEN-Thousands: Most of the "marked green" wiring is good, "rosa / pink" wiring is good --- want to establish a permanent jumpering "my orange wire, blue 'A' " --- do You get the 1000-points bonus at end of a ball ?
--- when You are not rewarded with Bonus-TEN-Thousands: Establish the permanent jumpering "my orange wire, blue 'A' " --- do You get the 1000-points bonus at end of a ball ?

When no luck
--- when You get the 5000 points on the Top-Eject-Hole: Establish (rather easy to do) the permanent jumpering "red line, blue B".
--- when You do NOT get the 5000 points on the Top-Eject-Hole: Establish (rather complicated to do) the permanent jumpering burgundy-red, blue C".
Do You get the 1000-points bonus at end of a ball ?

If no luck: Establish jumpering "D" and "E" --- You now have jumpered almost-every*** wire --- if still no luck: The switches in the wiring are of interest.

On the bottom of my JPG: The "brown 1" shows how the 1000-Point-Relay is made pulling when a player has some 900 points on the Score-Drum and makes another 100 points --- the activated 1000-points-relay then makes the 1000-point-Score-Drum step.
The "brown 2" shows another "Self-Hold-Switch, on the 1000-point-relay" --- this relay must be pulling long - long enough so the Score-Drum can signalize "I am ready to really give the 1000 points": The travelling plunger on the Score-Drum "AT END / READY to really give the points" - plunger opens a switch and so the 1000 point-relay is made "quit pulling" (Relay and Score-Drum do "work together").

almost-every*** wire: The only wire not jumpered is the wire yellow from transformer-lug-Yellow to "Switch-A on Impulse-Wheel" --- this SCM-Imp-A switch is also involved to coin-up the credit / replay counter when You throw-in coins --- question: does "coining up" works ?

The pin does step to second ball --- how about to third / fourth / fifth ball - Game Over ? How about playing a 2,3,4 player game ? Greetings Rolf

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Hi Shawn
to post-12, rather difficult to clip-on a Jumper-Wire at SCM-IMP-A: When the schematics shows a DIRECT connection to "some other stuff" - AND that "other stuff" is functioning: We can clip-on at "other stuff" --- and clipping-on a Jumper-Wire at "Switch on 25-Cent-RELAY or 10-Cent-RELAY" is for sure less complicated than clip-on at SCM-IMP-A.

When we have to (lets say) work to do on SCM-1C - we must consider:Score-Motor-Wheel-1 is NOT the first wheel next to the real motor ...
Greetings Rolf

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