I think it has something to do with the bonus unit reset solenoid CD-29-1600 and/or the score motor.?

Here's a example of how things should work.

Knipsel1_(resized).PNG
Knipsel2_(resized).PNG

Hi heiber
I look into ipdb-Manual and ipdb-schema. It looks a bit complicated - has to do with "3 balls per play <-> 5 balls per play", "liberal <-> conservative". You do not (yet) wrote about Your settings - I do write "in general":

In the schema at G-13 I see the "Bonus Unit Step-UP Solenoid". It is activated through "closing Score-Motor-Switch-6D (M&B-Switch moving), a "Switch on Outhole-Relay***" not interesting, a "Switch on Top Hole Relay" interesting, a "Switch on Drop Target Relay" interesting.

"Switch on Outhole-Relay***" - I believe - When the pin changes to the next ball: It gives You one Bonus for free.

"Top Hole Relay" I see at schema-G-40 - the "Switch underneath the Hole" - a reference to "C-39" -> there its getting complicated.
"Drop Target Relay" I see at schema-G-24 -> its getting complicated: Score-Motor-Switches, Switches "3 <-> 5 Balls" , a "Switch on Center-Target-Relay", "Switches Bottom left and right Return Lanes", "Switches activated when a Drop-Down-Target fells / falls".

Many switches can cause YOUR problem - I would first find out 1) "Does Top-Hole-Relay ALWAYS pulls when it should" - 2) "Does Drop Target Relay ALWAYS pulls when it should".
Please write about Your settings in the pin.
Greetings Rolf

Hi heiber
thanks for precise answer. Yes, when a EM-pin is busy giving 50 or 500 points to the Score-Reels: ANOTHER "activating of some feature" at the same time misses the Score-reels etc.

Whenever a fault happens "sometimes BUT NOT ALWAYS": I suspect: Do to vibration / "bangs of plungers" / shaking the pin now and then: Somewhere a wire has broken-off a solder-lug - wires are stiff and tend to stay in place (NOW THERE IS contact) - shaking etc -> the broken-off end moves a tiny bit -> NO contact -> and so on ...

I also think it is "BOTH RELAYS ARE DOING THE JOB" - the fault is near (in schema and reality) the "Bonus-Unit-Step-UP-Solenoid / -Coil.

I look into the schema AROUND G-13 -> There is a "Switch on Tilt-Relay, wire-color-15-White-Red, wire-color-10-simply-RED are soldered-on -> check the Tilt-Relay and its Normally-Closed Switch (switch oxidated - not closing properly ?).

Look at the Bonus-Unit-Step-UP-Coil: wire-10-simply-RED and wire-21-2-Blue-Red soldered-on to the Coil.

Grab every wire and gently pull a bit -> soldered-on or broken-off ?
We might have to look further - BUT, You said it: Mal-function on BOTH Relays - chances are small that BOTH RELAYS are faulty ((( we keep in mind: an probality of 1% can happen (about 1% of the time) ))).
Greetings Rolf

Hi heiber
if You do NOT find a dirty switch / wire broken-off - We might think of: Using a "48 Volt-Test-Light" mounting PARALLEL to the "COIL on Bonus-Step-UP" - for to GUARANTEE: NO mechanical problem - but lets see if You find the fault.
Greetings Rolf

I dont have that machine, but, that 6-d switch is a make/break switch. in the pic, it will rout power to 0-90 unit, supposed for simple points collected.
when the motor turns, it will switch the power to 74-1. if either of those 3 relays are active, power will go to the bonus unit step up.
if you remove a switch stack, get a nut to fit the screw, and install on the stack to keep it from falling apart.

the 6-d switch is make/break. that means 3 blades with the one in the center longer, and moved by the relay.
there can be any combination in a stack. normally open, like most on your pic. normally closed, like the tilt at bottom of pic.
Look at any relay on that pin, pick a switch, push the plate down with your finger, does the switch open, or close?
the plate has the plastic ladder part connected to it, and the switches that move are longer, and stick through a slot in the plastic part.
if the moving switch blade is on top, and closes when plate pushed down, it is a normally open switch.
if the moving blade is on the bottom, it is a normally closed switch.
if the moving blade is in the middle of 3, it is a make break switch.

Hi heiber
I apologize for (reading - forgetting about - ) not writing.

Funny, wikipedia shows a Night-Rider-Score-Motor: http://www.pinwiki.com/wiki/index.php?title=EM_Repair#Bally_Score_Motor -> http://www.pinwiki.com/wiki/index.php?title=File:BallyScoreMotor3-4View.jpg -> Number-1 is near the Motor -> I see four switches on Nylon-Wheel-6, Bottom is "A", then B,C, D is on top - nice for looking at - do NOT unscrew the switchstack.

Unplug the 110 VAC Main-Line-Cord (Safety Reason) -> turn the Nylon wheels by hand -> watch how the switchstack on Wheel moves down and later up again -> can You see the moving of the MIDDLE Blade in switch-D ? does it look good ? take a stripe of "cardbord" (NOT shiny colored-postcard-type) You want tu use it instead of "sandpaper" - it shall be a bit "rough". Put the stripe into the "open part of the switch (at Beginning- / Zero-Position / "NOT actuated") -> turn the Nylon-Wheel until the switch is activated -> NOW carefully move the stripe a bit around.
OK - do the same witch the other "part / half" of switch-6D: FIRST turn the Motor -> You can sneak-in the stripe -> turn further -> stripe is "tucked" -> carefully move the stripe around a bit.

Still I believe: A Wire can be broken-off a Solder-Lug - wires are stiff - they "stay in place" - well sometimes they do - sometimes they do not ...
Grab the wires and pull a bit -> securely soldered-on ?
Greetings Rolf

Hi heiber
lets use a Test-Lite for testing. You have 110 VAC in Your house. You have a simple bedroom-Lite (two prongs) - Bally-pins uses 48VAC for the relays / steppers etc. The "Bedroom-TEST-Lite" will not shine VERY bright - but it will light-up.

Whenever You just look into the pin, when You just fumble around / work: UNPLUG the 110VAC Main-Cord (Safety Reason).
Unplug the 110 VAC cord -> look at the transformer -> Do You see a wire-RED-White running from a "Lug on transformer" to the 48VAC-10-Ampere-Fuse ? The other side of the fuse has one or two wires-color-BLACK soldered-on. Do You see that ? If not: do NOT proceed - report -> we will look at ...
On the same level at the transformer - a bit to the side - "Transformer-Lug-YELLOW": Two Yellowish-light-brownish wires are soldered-on. Do You see that ? If not: Do NOT proceed - report -> we will look at ...

Look at my JPG: "Violet": IT IS TABOU !!! ONLY the "Red-Dot" and the "Yellow-brown CIRCLE" are allowed - YOU ALWAYS MUST HAVE THE FUSE IN THE CIRCUITRY (WHEN JUMPERING).
Connect one side of Your Bedroom-Lite (a oldfashioned Edison-type 20 / 40 / 60 Watt bulb - NO NEON-Type, NO LED-Type) - connect one side to transformer-Yellow (permanent, solid connection). With the other side (using a wire) -> TIP ON THE FUSE "side-wire-color-BLACK". Practice a bit. Lay the open end NEAR the fuse - NOT touching anything.

Plug-in the 110VAC-Main-cord, turn-on, start a game. CAREFULLY take the end of the wire and (again) touch onto "Fuse-side-wire-color-BLACK" -> does the Test-Lite lites up ? If not: Do NOT proceed - report -> we will look at ...

Turn off, unplug 110 VAC and prepare "Test-green-1": You mount one side of the test-lite to the middle blade of Score-Motor-6D - where Wire-Yellow is soldered-on. The other end of wire of the Test-Lite (again) lay NEAR the fuse.
Plug-in 110 VAC, turn on, start a game -> Reset is done -> pin idles -> CAREFULLY take the end of the wire and (again) touch onto "Fuse-side-wire-color-BLACK" -> does the Test-Lite lites up ? If not: Do NOT proceed - report -> we will look at ...

Turn off, unplug 110 VAC and prepare "Test-green-2": You mount one side of the test-lite to the lower blade of Score-Motor-6D - where Wire-Black-Red is soldered-on. The other end of wire of the Test-Lite (again) lay NEAR the fuse.
Plug-in 110 VAC, turn on, start a game -> Reset is done -> pin idles -> CAREFULLY take the end of the wire and (again) touch onto "Fuse-side-wire-color-BLACK" -> does the Test-Lite lites up ? If not: Do NOT proceed - report -> we will look at ...

Unplug 110VAC again - have a look at Your Score-Motor (and my JPG) - Dou You have a Service-Jack to UNPLUG the Score-Motor ? sometimes we want to turn the score.Motor BY HAND. If You do not have such a Service-Jack: Do NOT proceed - report -> we will look at ...

OK - unplug the Service-Jack (Score-Motor) - Can you turn (grabbing a wheel) the wheels - moving -> grabbing again -> moving -> "a half round = 180 degrees" ? If not: Do NOT proceed - report -> we will look at ...

PLUG-IN THE SERVICE-JACK (SCORE-MOTOR), plug-in 110 VAC -> turn-on and start a game -> reset -> idle -> NOW unplug the Service-Jack (Score-Motor) -> Establish "Test-green-2" -> the test-Lite lights-up. NOW turn the Score-Motor by hand -> when Switchstack-6 is activated: DOES THE TESTLITE QUIT LIGHTEN ? If not: Do NOT proceed - report -> we will look at ...
You have just tested "Does Switch-6D open the part-that-shall-open".

Unplug 110 VAC and prepare "Test-Green-3": You clip-on at Upper blade (color-Orange-Green). Plug-in 110 VAC (and Score-Motor-Service-Jack), turn-on, start a game -> reset -> idle -> NOW unplug the Service-Jack (Score-Motor) -> Establish "Test-green-3" -> the test-Lite does NOT lights-up. NOW turn the Score-Motor by hand -> when Switchstack-6 is activated: DOES THE TESTLITE LIGHTs-UP ? If not: Do NOT proceed - report -> we will look at ...
You have just tested "Does Switch-6D close the part-that-shall-close" = THE Part You suspect.

PLEASE: BE VERY CAREFUL: 48VAC can kill YOU !!!
Greetings Rolf

cNight-rider-snippet_(resized).jpg

757px-BallyScoreMotor3-4View_(resized).jpg

199px-Bally_Motor_Switch_1_At_Rest_(resized).JPG

733px-Bally_Motor_Switch_1_Motor_Running_(resized).JPG

Hi heiber
yes - I did take my "nightlight" (60 Watts, 230 VAC) - it has two prongs - i attach a wire (A) to prong-1 and I attach a wire (B) to prong-2. I do not have to bother "A <-> transformer-Yellow" OR "B <-> transformer-Yellow" - it does NOT matter.

Bally runs with 48 VAC !!! Steve fury shws a testlight for WILLIAMS-24 VAC !!!, here:
https://pinside.com/pinball/forum/topic/reading-gottlieb-schematics post-12. In post-10 he writes about testing (I also made myself this handy tool).

You can take FOUR automotive 12Volt bulbs -> 4 times 12 = 48 Volt -> a Bally-Testlight ...
(((working in / on another topic I had to test 110 VAC -> I took my nightlight -> and afterwards - just for fun: I tried my "built for 230 Volt nightlight" on Williams-24VAC -> I can see it glowing.)))

Try your nightlight or make Yourself a "four times 12 Volt automotive "48 Volt" testlight" - whatever you like

BUT: ALWAYS HAVE THE FUSE IN YOUR CIRCUITRY !!!
Greetings Rolf

Hi heiber
good discovery / detection - is the current "cut out too soon" ? This can happen - usually it happens ALWAYS --- if it happens SOMETIMES: It "can" be a dirty switch - sometimes working - sometimes not proper working. IT ALSO CAN (!) BE A WIRE BROKEN-OFF - but (as wires are stiff) the wire has contact to the Solder-Lug (it has broken-off) - then shaking the pin / vibration -> end-of-wire moves just a bit to the side -> NO connection -> shaking again -> connection and so on and on.
WHENEVER You look at a switch: Grab the wires and gently pull - soldered-on ?

MANY relays have a so called "Self-Hold-Switch***" the relay must stay pulled for quite a while (long time). So for this there is a Normally-Open-switch mounted ON THE RELAY (usually on the bottom of the switch-stack) -> relay starts pulling -> activates switches -> CLOSES this Self-Holf-Switch: NOW the relay has made "Current to me forever". (((After a while ANOTHER switch (somewhere) opens the Self-Hold-Circuitry and the relay lets go and by that opens its self-Hold-Switch))).

"Self-Hold-Switch***": Easy to be found: From one side of the "coil of the relay" a short wire runs to a "Switch mounted on the relay": THIS is the Self-Hold-Switch - it must close and securely stay closed.

"Bonus shall step-up because of TOP-Hole" -> Schema-G-40 shows the coil - a bit above (still G-40) a switch is drawn, named "Top Hole Re." - the Self-Hold-Switch, wire-93-Gray-Yellow is soldered-on and wire-14-Red-Green is soldered-on. Examine this switch.

"Bonus shall step-up because of Drop-Target" -> Schema-G-24 shows the coil - above to the right, H-24 shows a switch named "Drop Target Re." - the Self-Hold-Switch, wire-61-Brown-Red is soldered-on, (maybe) wire-78-Orange-Black is soldered-on. Examine this switch.
Greetings Rolf

Hi heiber
hmm, what means "hold consistently even when the Bonus does not advance" ?

There are more switches to check.

BUT - for to test the theory "Self-Hold-Switches do not work properly - do they ? / do they sometimes ? / do they never ?": Lets build-in the "FAULT" !!!: These switches ARE FAULTY - THEY NEVER CLOSE !!! . Doing this -> the pin will show symptoms - is now ALWAYS the same old fault - always ? Is there a NEW fault ?

Please do that simple test and write about "This happens ...".
Sneak-in a "Stripe of paper for insulation" in-between the two blades / contact-points" of the "Self-Hold-Switch on Top-Hole-Relay" - do the same on "Drop-Target Relay".
I wonder, what symptoms You get with these "sneaked-in faults" - please write.
Greetings Rolf

Hi heiber
the symptoms are other / worse than expected. so take-out the stripes of paper.
Lets look at another "possibly faulty" switch - the Make-and-Brake-Switch (3 blades) Score-Motor-8-C.

Look at the schema -> G-40 is "Coil on Top-Hole-Relay". A bit above is its "Self-Hold-Switch" - further up is an arrow pointing "to H-32". We look at H-32 and see "Arrow pointing to H-40". There is a wire connecting in between. So if "Score-Motor-Wheel-8-Switch-B (second from the bottom) is faulty / dirty: The "Self-Hold-Mechanism" does not work.
Look here: http://www.pinwiki.com/wiki/index.php?title=EM_Repair#Score_Motor -> http://www.pinwiki.com/wiki/index.php?title=File:BallyScoreMotorFrontView.jpg -> from left to right count the wheels: First, 2nd, 3 ... 8th wheel, almost at the bottom of the Stack , the 2nd-lowest: When the Motor does NOT run: IS THE PART "CLOSING" REALLY CLOSING ?
Greetings Rolf

Hi Heiber
did You do the test with the Test-Lite on Score-Motor-Switch-6-D ?
Lets look at schema-J-12 and look downwards: Wire-Yellow -> SCM-6-D -> to the right and then down -> "Switches on Top-Hole- / Drop-Target- / Outhole-Relay" -> down and to the left -> the "Bonus-Unit STEP-UP-COIL" -> to the left -> "Switch*** on Tilt-Relay" -> to the left -> -> -> "Switch*** on Game-Over-Relay" -> -> -> "Switch*** on Reset-Relay -> down, left, down -> fuse -> down to the transformer-power-side.
If all switches are good and closed - and the wires in-between soldered-on: The Bounus-Unit step-up coil fires.
Please write about "Test with Test-Light" Score-Motor-6-D.

"Switch***": If one of these mentioned switches is "no good": A LOT OF THE FUNCTIONALITY in Playfield-Features would not work properly - so I doubt tha one of these switches is "faulty".
Greetings Rolf

Hi heiber
lets look at the snippet - JPG in post-16.
Sometimes it is REALLY difficult / impossible to clip-on a Gator-Clip at a lug somewhere. We should clip-on THERE - but its just not room enough ...

We then make a compromise - we say: IF WE COULD CLIP-ON THERE: WE WOULD HAVE A 100% PRECISE ANSWER.
When we find another place - that other place HAS DIRECT CONNECTION to "where we would like - but cannot clip-on" - we have that connecting wire ALSO in our testing - IF (if) this connecting wire is (also) faulty: We might conclude something wrong - assuming the connecting wire is good (what it is not) -> we conclude wrong.

OK, look at the JPG -> a wire-color-81-Black-Red runs (downwards) from "Lug-on-Score-Motor-Switch-6-D -> runs to "Switch on Extraball-Relay". The same wire (and wire-color) runs to "Switches on Tilt-Relay". The same wire (and wire-color) runs to "Switch on Ball-Index-Relay".

There are also connecting wires starting at the other Lug-on-SCM-6-D -> to Top-Hole-Relay / Outhole-Relay / Drop-Target-Relay.

"Wire-YELLOW" IS ABUNDANT in the pin - just an example: There is a switch drawn nearby - Make-AND-Brake-Switch on Outhole-Relay" - with wire-YELLOW ... (((Also on lugs on switches on Score-Motor: Plenty of Wire-Yellow attached ...

We CAN use "more comfortable places to clip-on" - BUT we MUST consider: We use an (other) wire in our testing --- When (when) THIS other wire is bad -> we get results that lead us "astray". Greetings Rolf

Hi heiber
The result of your simple test was :" Bonus-Unit NEVER steps-up not through Outhole-Relay, not through Top-Hole-Feature, not through Drop-Target-Feature ?

Long time ago You mentioned: It works through the Outhole-feature - sometimes , sometimes not: the other two features.
You stated: "Self-Hold-Functionality Top-Hole-Relay" works.
You stated: "Self-Hold-Functionality Drop-Target-Relay" works.

Look at the JPG: "Light-blue line (wiring) works". The fault must be in the "Dark-blue wiring" - You stated: the two relays STAY PULLED - You stated: The two switches ARE clean and make Contact. Then the fault must be in the wiring (Dark-blue).
Greetings Rolf

cNight-rider-snippet2_(resized).jpg

Hi heiber
I do not own a Night Rider. I used to play it in the late 70ies - a pin well worth the time we spend "looking for the fault" ...
Attention: the picture (post-32) I made "a fake switch-stack 6" - I have taken: http://www.pinwiki.com/wiki/index.php?title=File:Bally_Motor_Switch_1_At_Rest.JPG and http://www.pinwiki.com/wiki/index.php?title=File:Bally_Motor_Switch_1_Motor_Running.JPG
and then I made the bakelit wheel - this picture does NOT show Switchstack-6.

I do agree: the top switch (encircled) is switch-D.

I once read (have not made a link to that - but still remember): "Carefully checked schema and reality in the pin - TWO switches drawn in the schema BUT not mounted in the pin / ONE switch mounted in the pin BUT not drawn in the schema".

The schema may have a fault - telling us SCM-6-D --- BUT it is NOT SCM-6-D (grumble).

Your test is good: sneaking-in a stripe of paper to prevent closing -> the Unit does not work.
AS the Unit works -> conclusion: we are looking at the wrong switch ->

Can You find the WHEEL ? Let drain the ball several times and listen to the Step-Up-Unit (noise) and LOOK at the Score-Motor: When You HEAR the Step-up-Unit: WHICH Switch-Stack is lifted AT THIS VERY MOMENT ? Look here: http://www.pinwiki.com/wiki/index.php?title=File:BallyScoreMotorFrontView.jpg from the left to the right: Wheel-3, -4, -5, -6, -7, -8, -10: They ALL have a "stud / mountain" on the outside of the wheel - ONE to lift its switchstack - when the Motor turns -> with a little offset in time: First wheel-3 lifts its switch-stack -> then Wheel-4 -> then -5, -6, -7, -8, -10. Can you find out WHICH WHEEL DOES THE JOB (Outhole-Relay pulling) ? So you ONLY have to investigate on THAT specific switch-stack -> looking for a Make-and-Brake-Switch with wire "Yellow (middle blade)", wire "Black-Red (lower blade)", wire "Orange-Green (upper blade)".

When I look here: http://www.pinwiki.com/wiki/index.php?title=File:BallyScoreMotorTopView.jpg : I do NOT see on Wheel-6, top position SUCH COLORS -> we might have come across a "FAULT IN THE SCHEMA".
Greetings Rolf

Hi heiber
good - You made progress.
second: In switzerland its getting late - soon I should go to sleep - no more pinside for the rest of the day ...
First: My Laptop computer has the nasty habit to turn-off the screen - it started this behavior yesterday - every half hour. By now: every 5 minutes - every 4, 3, 2 minutes -> tomorrow I must try to see my computer-doctor ...
Greetings Rolf

Hi heiber
I'm back again - the "Backscreen-Lighting" on my ThinkPad-PC is shot - for a temporary solution: another (standalone) Sceen ( I have never used my laptop-pc abroad - I might use that other screen forever ...)
"Over the Top Function" -> schema-G-6 is a relay (Over the Top DELAY Relay) - I BELIEVE (means I am not sure): This relay is geting pulsed "faulty". So look at schema-G/H-4/5/6 (its is just on the borderline G/H) - an arrow points and the text "Players 100,000 Relay" -> "1st" I BELIEVE IS WRONG, I believe the "Normally-Closed-Switch on First-Player-100000-Point-Relay is faulty - when moved: it stays (faulty) closed.
Please check that N.C.-Switch, it has wire-13-Red-Yellow soldered-on, it has wire-36-Yellow-Brown soldered-on.
(((I am just curios: Does the bulb (a flashing-Number-455-lamp) on the relay flashes-up - for just an instant ? --- Bally invented the funny "DELAY-Relay" and the DELAY is done with / through a 455-Flashing-Bulb: It is a 6VAC-lamp - avtivated by 48 VAC - way too much electrictity for a cozy / comfortable / relaxed flashing (think of a Game-Over-Bulb) -> almost immediately after getting energy: this 455-bulb CUTS the SElf-Hold-Circuitry. VERY IMPORTANT: If this bulb is SHOT: The DELAY-RELAY does not work as it should - it has NO DELAY (as the bulb IS SHOT).)))
Greetings Rolf