Fingers on a stepper unit dirty? Or the contacts themselves (rivots)

Under the playfield or in the bottom of the pin you will see a square pc board with small copper rivots that the switches travel on. Ususally with one or two coils.

Post #952 in Nics pinball tour. There is a picture of one.

Yes similair to that and the contact are on the other side of it.

Hi Justmc16 +
jedi42 had a completely different problem - he started this topic: https://pinside.com/pinball/forum/topic/no-power-to-doodle-bug-playfield --- in his post-11 he writes "have submitted the paginated schematics to ipdb.org" --- this was more than 60 days ago. It takes time for ipdb.org to handle the incoming stuff ...

When You make an "righthand-side mouse-click on that PDF in post-11 - then choose "save target as": You can make Yourself an copy of this 6-page document. It is tricky to move around in that PDF / Copy ...
So I made JPGs and put together the pages into one continuous schematics (in the form of an JPG and also PDF) I can send You a copy of my work --- range 2.5 MB to 6 MB data - when You send me an personal message with an E-Mail-Address in Your message.

To Your problem - the "not advancing" - it is NOT the unit shown in Your post-6 --- see my JPG --- the stepping is done by the so-called "Number-Match-Unit". ipdb.org has an manual to the 4-Player-Version of the pin (Dipsy Doodle) here http://mirror2.ipdb.org/files/683/Williams_1970_Dipsy_Doodle_Instruction_Manual.pdf and on page-8 (ori-6) I can read: "Match Unit (Step-Up-Coil) is mounted on the Insert means in the Backbox --- here http://www.ipdb.org/showpic.pl?id=703&picno=48479 to the right of the Replay-Counter --- in Your pin: Is there a paper tag TELLING "No. Match Unit" ?
Let a friend play and YOU watch this Unit in the Backbox --- question: Does this Unit ever steps ? Greetings Rolf

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Hi Justmc16
in post-3 You +/- write "am a newbie" --- no problem - we do troubleshoot in small steps.
DANGER - electricity can kill You --- whenever You work in the pin or just look into the pin: HAVE the main power cord unpluggrd. ONLY plug-in (and start a game) when You need electricity for a test.

Have the main power cord unplugged - look at Your transformer - look at http://www.ipdb.org/showpic.pl?id=703&picno=41663&zoom=1 --- dominant the two yellowish-muddy-brownish wires called wire Yellow (this is the return side (common) to the transformer). Clip-on an Jumper-Wire at this transformer-lug "Yellow" and take the other end of the Jumper-Wire through the open Coin-Door out into the open --- the free end of the Jumper-Wire shall not touch metal.
Take an second Jumper-Wire --- look at the Coil on Your Number Match Unit --- one side has two wires of color-red soldered-on --- the other side has one wire of color-orange-red soldered-on. Do NOT proceed when You are not 100% sure You actually see wire-of-color-orange-yellow !!!

Clip-on the second Jumper-Wire at solder-lug orange-yellow and take the other end of the Jumper-wire out into the open --- NEAR the first Jumper-Wire --- NOT touching metal.

Plug-in the main power cord - start a game - when You can play: NOW grab the two Jumper-Wires at "insulation" - then tip together the free ends and pull apart --- big question: Does the Coil on the Number-Match-Unit fire and (hopefully) the Unit makes a step ? Write about.

Your picture in post-12 shows an Adjustment-Switch --- let it "as is".
We will come to "post-13, Bell".

I live in Switzerland (south of Germany) --- we are ahead in time to the USA about 8 to 10 hours. This might be the last post I write "today" - greetings Rolf

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Hi Justmc16
its good when You ask when You are not 100% sure about a thing.
I have taken Your picture and added some colored lines ending at the solder-lugs on Your transformer. Also look at the top of the JPG in post-14.
"My green line points to solder-lug 'wire-color-G-Y-W-Green-Yellow-White' - this is POWER-Side of the 6VAC-Lamp-Circuitry"
"My orange dot sits on the solder-lug 'Yellow' having soldered-on two wires of muddy-light-brownish-yellowish color - this is Return-Side (+/- incoming side) for BOTH circuitrys - for the 6VAC as well as for the 24VAC circuitrys - we always refer to the wire calling it wire-yellow"
"My black line points to solder-lug 'wire-color-B-Y-W-Black-Yellow-White' - this is 24VAC?*** POWER-SIDE of the relays and stepper circuitry"
"My grey line points to solder-lug 'no-color-mentioned - has text 'Low Line Voltage Tap' - this is the 26VAC?*** POWER-SIDE of the relays and stepper circuitry"

24VAC?*** and 26VAC?*** POWER: We call these two lugs "Low-Tap" and "High-Tap" --- and the manufacturer uses the word "Normal Tap" or avoids using a word (implying 'Normal') --- confusing --- maybe Your wire / my grey line is 'High Tap" - maybe it is "Low Tap" - well, whatever -
let the wiring in Your pin "as is" --- clip-on the Jumper-Wire at "my orange dot" - the solder-lug-Yellow on the transformer.

Do NEVER TOUCH the solder-lug "my green line points to"
Do NEVER TOUCH the solder-lug "my black line points to"
Do NEVER TOUCH the solder-lug "my grey line points to"
as these are POWER solder-lugs --- NEVER, never touch.
Greetings Rolf

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