Williams Grand Prix (1976) Ball not entering play after Drain

By ShawnandLacy

1 month ago


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  • Latest reply 1 month ago by rolf_martin_062
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#1 39 days ago

I have a Grand Prix that steps down the bonus (but does not award points) when the ball drains and then nothing happens. When you press start the ball kicks out and both 5000 point bonus lights light up. When points are scored the "Ball-Index-Relay" does not pull-in. I have cleaned all of the stepper units and switch contacts. Everything seems to be making proper connections but this is the first EM I have worked on, so there may be something I am not seeing. Anyone have any thoughts on this?

#2 39 days ago

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

#3 39 days ago

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

#4 39 days ago

The Left-Bonus-Relay pulls in until it steps down all the way then it stops pulling. When manually actuating the Outhole-Relay the Score Motor turns, both Left and Right Bonus-Relays try to step down and the Outhole Kicker fires.

#5 39 days ago

The Ball-Index-Relay stays pulling but will stop and advance the ball count if I manually actuate the Outhole-Relay.

#6 39 days ago

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

#7 39 days ago

Thanks for all the help Rolf

I was wrong about the Bonus Stepper Units they both are stepping up.

Still no points given for bonus but manually activating the Outhole-Relay does kick out the second ball.


#8 39 days ago

When I manually actuate the Ball-Index-Relay it is buzzing fairly loudly while pulling in.

#9 39 days ago

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

#10 39 days ago

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.

0Grand-Prix-Work-20 (resized).jpg

#11 38 days ago

Hi Rolf
The Coil does not get hot after a few minutes of pulling.

"Manually" closing switch A on the Ball-Index-Relay does cause it to pull and keep pulling. "Manually" closing switch A on the Outhole-Relay causes it to pull but only while contact is made. I attached wires so I can remotely close switch A on the Ball-Index-Relay.

The Rod on the Bonus unit does move the Make-Brake-Switch when moving from One-Bonus down to Zero-Bonus.

I think the previous owner did something to the tilt pendulum as it does not function but if I push the Tilt-Relay on it does cause the Ball-Index-Relay to pull in.

All questioned contacts seem to be in good shape and functioning properly.

Sorry to reply so late, long day at work.

Thanks again for all of your help. Shawn

#12 37 days ago

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

0Grand-Prix-Work-21 (resized).jpg

#13 37 days ago

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

0Grand-Prix-Work-22 (resized).jpg

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