I think that Williams space mission also has the tilt rollover.

Question #1 score reel does not have a 9th position carry over.
Question #2 score reel at zero position.
Question #3 score reel at any number 1-8 position.
Question #4 score reel at 9th position.

The alternator relay is controlled by a blade switch that is cam controlled on the 00-90 match unit stepper.

A more advanced question
In what 3 applications does a AC relay not use the full coil voltage supplied by the transformer.

Hint: mostly found in gottlieb machines

I thought about the resistor as a correct answer, but it isn’t 1 of the 3.
You are close on the second, can you explain more about it?

Wow a chicken dinner. I want it from HFC (Hillary fried chicken) where the chicken dinner contains 2 small breasts, 2 large thighs, and a bunch of left wings.

Answers to your 4 questions
#1 10’s score reel pcb is needed for the match circuit.
#2 100’s score reel doesn’t need a pcb. No circuit used to use one.
#3&4 1000’s and 10,000’s score reels needed for replay circuit . Both boards increase combinations for a replay setting.

Check the player control & outs unit for advancing and resetting correctly.
Does it advance when it shouldn’t?
How does it function on a 2 player game?

When chimes don’t work #1
check the chime switch on its scoring relay.
#2 check the coil for proper resistance and if it’s the proper coil number.
#3 coil sleeve and plunger are dirty.
#4 plunger return cushion is worn out and sticky holding the plunger down.
#5 coil slip on connector is loose or came off.

I forgot one. The coil plunger plastic tip is worn out or missing.

The lock relay in a Williams space mission era machine only does one thing.
When the machine is reset and ready to play and the on/off switch is turned off then on a pulse will be sent to the game over trip relay, putting the machine in game over mode.

Question #1 I’m not sure of the answer. I would say to jumper certain wires on the ball count unit?
Question #2 I think the A switch is to pulse the score reel coil during reset.
The B switch is in parallel with all of the other score reel B switches in the reset relay hold in circuit.
The C switch is the 9th position carryover to advance the 10,000 score reel.

The series relay and the coils in series with it are correct for 2 out of 3.
The resistor answer and description is correct also.
The last answer is when a coil is used in the lights voltage circuitry.
Mostly used in a bonus circuit.
Congrats well done.

Check out the target alpha double bonus post. Schematics aren’t available on IPDB for gottlieb machines. Bonus unit scanning will use this type of relay also, z relay?

Check the tilt switches, slam switches, and mechanical board bank reset.

Answer #1 parallel switch with the other score reels. Always open the circuit will think that the score reel is on zero, no matter what position it’s on.
Answer #2 always closed the circuit will think that there’s a score reel that needs resetting yet, so the reset relay stays pulled in and the score motor continues running.
Answer #3 score reel reset switch
Always open , the score reel will never reset on #s 1-9.
Answer #4 always closed, the score reel will always get pulses to try to find zero position.
Answer #5 carryover switch
Always open carryover from 9-10 points on the score reels will never happen.
Answer #6 always closed
Carryover will always happen no matter what position the score reel is at.
Example: instead of scoring 1 point you would score 11.

Post #83 answer
Continuous extra balls
Williams grand prix
The extra ball relays hold circuit is controlled by a series/parallel network of switches.
A NC switch on each of the score relays are connected in series to the extra ball relay hold switch.
A. NO switch on the ball index relay is wired in parallel is also in the hold circuit.
List of events
While playing you score an extra ball, the extra ball relay pulls in and stays pulled in because the ball index relay is already pulled in.
After the ball drains the bonus will score, the outhole relay will pull in, release the ball index relay, and kick the ball to the shooting lane.
Now the extra ball relay is relying on the scoring relays to open the extra ball relay hold circuit.
Once ball is plunged the first scoring that fires will be doing 2 things.
The first is the NC switch will be opening the extra ball relay, and the second is a NO switch that will be pulsing the ball index relay back on.
To keep the problem from happening regap the NC switches so that they open right at the start of the relay armature movement to increase the time the extra ball relay has to open.
Also the ball index relay switch for the hold circuit should be checked for a not to close gap. If this is always closed the extra ball relay will never open.

Post #70
Shangri-la
Rollover button doesn’t score 1 point when rolled over
The 3 rollover buttons each have a NO switch to do 2 functions.
First the button has to pulse the latch in relay, lighting its pop bumper and change the pop bumper scoring.
And the second is to pulse the ones relay.
To accomplish this a make/break switch is on the latch in relay, so when the relay pulls in the m/b switch will transfer its power from the latch in relay coil to the ones relay.
So to get the 1 point during the initial hit of the button, is dependent on how long the rollover button switch is closed, and how quickly the m/b switch on the bank relay can switch to the ones relay.

Post #3
Machines that have Tilt rollovers
Add Aztec to the list.

Post#8
Final answer to why 1000’s relay stays closed and 1000 score reel stays energized.
Answer: the 1000’s relay has a hold circuit that consists of a NO switch on the 1000’s relay, a NC end of stroke switch on the 1000 score reel, and the player up disc.
As long as the player up disc is positioned correctly the problem is the end of stroke switch is not opening when the score reel coil pulls in, thus not opening the 1000’s relay.

By unsoldering the white/black wire and tapping it off eliminates the tilt rollover function.
Unsoldering the blue/white wire and soldering it to the middle blade increases the pulse time for the advance relay to pull in.

The remaining switch is the end of stroke switch (EOS switch).
This is a NC switch that is in the hold circuit to the score reel’s score relay.
When a score relay pulls in, it stays pulled in thru it’s NO hold switch, the score relay pulls in the score reel . Once the score reel pulls all the way in the NC EOS switch opens, releasing the score relay and completing the sequence.
The score reels that don’t have a EOS switch don’t have a score relay to energize them.

Post #104
Random match number
I would say that the manufacturer set up the match # lights this way so players can’t guess what # will come up at the end of the game.
If the match # was sequential a player might be able to guess if the match # will be either a odd or even in respect to playfield alternating lights, thus increasing their odds of matching.
The more free games you give away, the less money the machine makes.
But however you look at it you have a 1 in 10 chance of matching.
So after your game is done and the match # is ready to come on you have to ask yourself a question.
Do I feel lucky well do ya punk?

The only other switch might be the score reel wiping disc switch.
On some gottlieb machine score reels, a switch next to the EOS switch, called an isolation switch is used in the replay scoring circuit.

OXO questions
#1 with a 19 relay latch in bank, is that the longest bank of any EM pinball machine?
#2 with that long bank mounted down the middle of the playfield, how would you rate the difficulty of changing lamps on the XO grid?

Wow great find. That bank looks like an electrical work of art.
The Egg head machine probably has the most coils for a single player machine and OXO has most coils for a four player machine.

The 2 types of step units used for bonus are the single step up/ single step reset
The other type of bonus unit uses an additional coil to change the single step reset to a full one pulse resetting.
Another variation of the single step up/ single step reset is the single step up/ full return reset.
Mostly used in ball count units for replay style machines.
The last is the continuous rotation style.
This type only has one coil for advancing rotation, no reset.
Mostly used in 00-90 or match units.

I remember some early machines had a jack for 10 replays for a double match. I’ve been wondering how they got that done.

What type of bonus unit has 2 coils, but it isn’t a step unit. And there isn’t any bonus ladder indicating lamps on the playfield.

Basically we have been talking about the electro/mechanical workings of a step unit. The rivet disc and wiper are an independent part of the step unit. But it still comes down to its a single step up/ single step down step unit regardless of what happens on the rivet disc. I agree that it might be a 3rd type of bonus unit, but it’s not a 5th type of step unit.

Along with old Chicago and bow and arrow, add delta queen to the list.

Is a grace shot a light hit on a target?
If a target doesn’t score when hit, either the score motor is running giving another score, or the target switch is gapped to far, the switch is dirty, or the target is a make/make switch and the 100 score is the 2nd make blade of the switch.

Target switches aren’t gapped close enough for a grace shot. If they were vibrations would close the switch causing extra scoring?

Post#139
Asks what type of bonus unit has 2 coils but doesn’t have a step unit or playfield ladder bonus lamps?
Answer: backglass animation , plastic balls used in a troft bonus unit used in top score , soccer etc.

Tighten down switch stacks.
File clean switches ( I like to use a ignition file) 3-4 swipes is usually enough.
Adjust the long blades to be straight or adjust to have a slight pull against the spring.
Adjust the NO blades so that the points close about halfway of the relay arm movement. The rest of the arm movement the points will wipe against themselves giving a cleaning effect.
Adjust the NC blades so that the switch opens before the halfway movement of the arm and has wiping when closing.
Inspect the mechanical movement of the arm and spring.
Mechanically operate the relay and check for proper switch operation.
Inspect all switch and coil wiring connections.
Blow off fillings and dust from relay.
Re-install relay

That’s a tough question. Can you give any hints?

Hi Rolf
Thank you for the hints.
I think I have the answer.
Both Bally and Williams have a lock relay, gottlieb has a hold relay.
And the lock relay has decreased its number of switches to the end of EM production.
The last remaining switch is in the game over circuit, the NC switch gapped to 70-80% sends a longer pulse to the game over latch/trip relay’s trip coil.
This is to insure the machine goes to game over when the on/off switch is pushed once or twice.

Here is a problem I’ve never been able to figure out.
The first apartment I moved into I moved my gottlieb king kool into. To keep the noise down I disconnected the black common wire from the chime unit. Only 1 black wire was used because the chime coils were daisy chained together. So you would think that without the black wire connected the chimes would stop working, but that wasn’t the case. Sometimes during gameplay I would hear a ghost chime sound. It wasn’t a full chime strike sound and it usually happened when a scoring replay was close. How is this possible without the black common wire connected?

SS machines that extensively use a power or ground braid and electronic components such as scr’s , darlington transistors , and fet’s to drive coils and lamps is totally different compared to em’s use of relay switches.
The actual ground or green wire from the line cord , if an em even had one would connect to the transformer frame and sometimes the coin door and had nothing to do with the other circuitry.