http://www.pinrepair.com/em/index.htm

Grab a schematic and look at all the switches in the start path...99.9% of the time it's an adjustment of a switch and/or cleaning of a switch/stepper. Not hard, but takes some time and patience to go through and figure it out. Schematic is the way to go so you don't end up adjusting things that are actually working and make it worse. If you are lucky, Dirtflipper will chime in and tell you the exact relays--he has memorized every Gottlieb schematic apparently.

Best advise -- read this, print it. & listen to dirtflipper when he chimes in.........

Please post some pics of the schematic...specifically where power is switched to the upper half. Looking at schematics of similar 2 player games of that era (Jumping Jack/Big Shot) I would check the game over relay (QB) and switches on the control bank and work back from there. The highlighted switch feeds power to the section you describe as not working.

Here's the section to look for (this is from Jumping Jack):

Capture.JPG

Pinrepair is your friend here. Did you check the fuses first and not just visually but with some kind of continuity tester?

It also may be a relay in the relationship that it isn't the relay not pulling in, but a misadjusted leaf switch or dirty contact.

Check the contact on the H relay, red-wh red-yellow

h.JPG

A switch on the Tilt or Game Over Relay will cause this. Also, be sure the Jones Plugs are seated and corrosion free on the entire machine.

It's not a fuse as some of the playfield coils do work and they all share the same fuse.

Back in the day many years ago when I was learning how to repair EM telephone exchanges (more relays than you can imagine!) an engineer told me to always work backwards when tracing through a schematic trying to track down a fault - this has advice has served me well over years.

Does the ball have to pass over a trough switch in the ball trough before it comes out to the shooter lane?

Hi osudrummer +
I refer to http://www.ipdb.org/showpic.pl?id=744&picno=18444 - the only action You have on the playfield is / are the "Kickout-Hole in the middle of the playfield" and the two "Kickback Lanes left and right" (?).
These features are wired different to / than all other "playfield features". Think of " a player got mad and banged a "severe tilt - Game Over" WHILE the ball IS in the Kickout-Hole / Kickback-Lane". When You start a new game - The pin WANTS to have the ball IN THE OUTHOLE (between the Flipper-Fingers): The pin fires these Kickout-Features until the ball is in the Outhole.

So do not bother about "strange, these features work - why not the others ?". I would concentrate on the question "woz, post-7, snippet enriched ->" the path I marked "RED"".
I would follow http://user.xmission.com/~daina/tips/pub/emTips.html -> http://user.xmission.com/~daina/tips/pub/tip0448.html : the sequence step by step (don't forget: Magnotron is a 4-player game - might be wired slightly different then Duotron).
I also like using "Jumper-Wires" to "narrow-down" - a Schema is NEEDED.

Does Your Duotron also have the "Relay Bank" as shown on Magnotron: http://www.ipdb.org/showpic.pl?id=744&picno=26189 ? SB-, SB1-, SB2-Relays should be in that "Relay Bank".

When working on Gottlieb pins having the "Relay Bank", looking for the cause of a strange behaviour I do my tests twice: The first time I have the "Relay-Bank" "State-AA, as is" - the second time I do before testing manually move the "Relay Bank" to "State-BB, moved or dropped or resetted - the other way" - then I do the same testing the second time. Gottliebs are strange. Greetings Rolf

P.S.: If You do not have "Schema / Manual": Buy, EVERY pin should have its complete documentation. Snippet-for-Duotron.jpg

This is important. I had no switch or coil activity on my Target Pool until that switch closed and opened again from the action of a ball rolling over it.

Hi osudrummer +
Great, You have a schema - I have taken the snippet You show in post-9 and show it with (added) Letters "A", "B" etc.
Look all over the schema , my "schema Far Out" tells me (near the drawing of the transformer): "Note: Circuit is shown with machine reset, ready for 1st player to shoot 1st ball AND LINE CORD UNPLUGGED".
I am sure (99%) Your schema also shows these "circumstances". Now, You want to play - Your pin is plugged-in, running, so the "Switch-A in my JPG" IS OTHER THAN DRAWN IN YOUR SCHEMA. Your "T-Tilt-Relay, my "B"" is not active, therefore the "Switch-"C"" is closed and the "H-Tilt-Hold-Relay - my "D"" is active , pulling, pulling, pulling constantly.
Lets assume You shake the pin a bit and make a "mild tilt" , "my Switch "E" closes -> "B" gets active, pulls -> "Switch-C" opens -> "H-Tilt-Hold-Relay "D" gets inactive AND "SWITCH-"A" changes position (now Switch-A is "as shown in the schema") - the "Self-Hold-(Part of)-Switch-A, Self-Hold-Circuitry for H-Tilt-Hold-Relay "D"" is open - the "T-Tilt-Relay "my B"" can get inactive (the pendulum tilt comes to a halt) -> "H-Tilt-Hold-Relay my "D"" stays inactive - until with a new ball -> "my Switch-"F"" again enables "H-Tilt-Hold-Relay my "D"" to pull and pull and pull ...

The "above written" is to make clear: You have started a game, You have a ball in the shooter lane, You want to play -> "my Switch-A" is "other than drawn in the schema". "Switch on SB2 - my "G"" is / should be "as drawn". "Switch on QB-Game-Over-Relay - my "H"" is / should be "as drawn".

Want to do a test with a "Jumper-Wire" ? - Would be more comfortable with two Juper-Wires having Gator-Clips ...
My description is for: Using two long wires (with insulation all around, but) - two inches of bare copper on all endings:
Turn-off the pin and unplug the Line-Cord ! Find the "Middle blade on my Switch-A***" and wrap one bare ending of "Jumper-Wire-Alpha" around the solder-lug having "Wire-color-Red-White" soldered-on (a solid wrapping around the lug). Carefully take the Jumper-Wire-Alpha with its other bare ending into the open.
Do the same with "Jumper-Wire-Beta": Find my "Switch-H***" on QB-Relay and wrap one ending around the solder-lug having "Wire-Color-Red-plus-White" soldered-on. Carefully take the Jumper-Wire-Beta with its other bare ending into the open.

Plug-in the Line-Cord, turn-on the pin, start a game -> after Reset -> hold Jumper-Wire-Alpha on its insulation, hold Jumper-Wire-Beta on its insulation -> and hold the bare endings together / make contact. Do the playfield features work ?

Switch-A***: A Make and Brake Switch, three blades, the middle blade has soldered-on: Wire-color-Red-White. An "outside blade has soldered-on: Wire-color-Red-Yellow. The other "outside blade has soldered-on: Wire-color-Yellow-plus-Green.
Switch-H***: A Switch with two blades. One blade has soldered-on: Wire-Red-plus-white. The other blade has soldered-on a blank Jumper (?) / a wire-color-Brown-White-Red (?).
Maybe want to look in the "list of Relays" in the schema -> (example) QB-Relay, 2A, 4B, 1C or such - this means (my example) QB-Relay has "2 Normally-Open Switches" - has "4 Normally-Closed Switches" - has "1 Make and Brake Switch".
Maybe You must look all over the schema and find all the "Switches on QB-Relay" -> looking at "color in schema" <-> "color-in the pin on the Switch-Stack" - You should jumper the "right" Switch on QB-Relay ...
Greetings Rolf zzzGtb-Duotron-pinside-JPG-04.jpg

The path needs to get through the make/break switch on H, the make/break switch on SB2, and the normally closed switch on QB.

So H needs to be energized, and the Control Bank needs to have reset at the end of the startup sequence to make sure SB2 and QB are not tripped. Then those switches should be in the correct state. But still could have dirty contacts, bad gaps, or a loose wire or other open along the way, so will want to check for that if the easy stuff doesn't find it first.

(Apologies if already covered; was away for a few days)

ooooh high tap. You are going to hell.

ie the red wire should be moved from high to "start"

yep

I'm a little late to the game but step one with any EM is to tighten the switch stack screws.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

And H is energized?

Next simplest thing to try is a jumper wire to bypass SB2 and QB to see if it will work brute force.

But since SB2 and QB are both on the Control Bank, another thing to check is for a loose or disconnected wire there in that bundle. The small bridge wires used can sometimes pop off, which will create an open. Can be hard to spot sometimes too.

By using a jumper wire and bypassing them, if it works, then you know the problem is isolated to there.

We typically just use alligator clips on each end of a wire. These can be purchased though (and some nicer ones have rubber covers over the clips).

You'll want to connect it to the RED-YEL wire coming off H and then to the RED+WH wire on the other side of QB (see your schematic).

But take a close look at the Control Bank where SB2 and QB are located, and follow the wiring there, to make sure there's a path from SB2 to QB. The wiring needs to enter the Control Bank to reach SB2, and then that RED+WH wire needs to leave the Control Bank after QB.

Hi osudrummer+
I added letters and numbers to the snippet of schema (Your post-9). If You want to "clip-on one side of a Jumper-Wire onto "A"" - but it is hard to get there: Look in the schema for DIRECT connection (a wire, but no switch in the wiring) -> maybe the solder-lug on "Switch on N-Relay" is easy to access -> "clip-on" Your Jumper-Wire at (my) "B". Maybe at C or D or E or F or G or H ?
The same with - instead of clipping-on onto "1": Want to use 2, 3, 4, 5, 6 ?
You must keep in mind: You clip-on onto another place - You have some wire in Your "Test-circuitry" - and that piece of wire can be broken inside the insulation (not visible). Also: (not shown in the schema): That piece of wire (You also have in Your Test-Circuitry) may run in the pin through a Jones-Plug - and the plug has oxidated (no contact). Greetings Rolf zzzGtb-Duotron-pinside-JPG-91.jpg

In addition to checking the fuse itself, check continuity/power on the wires connecting to the fuse blocks once the fuse it back in. I have a 1972 EM machine that was acting funky and it turned out to be that even though the fuse snapped in, it was somehow open, and I had to replace the fuse holder.. strange..

That jumper test only confirmed that there is in fact an open somewhere in the path from H to QB. But you still need to find more precisely where it is. I'd still suggest looking carefully on the Control bank where SB and QB are both located.

You can also just jumper over one switch at a time (H, SB, or QB), to further isolate. But pay particular attention to SB and QB.

Hi osudrummer +
lets assume You have jumpered "A<->1" (or "B<->1") , my JPG HERE. Results: With Jumper You have action on the playfield, without jumper You do not have action on the playfield. Conclusion: Alfa***: The Make and Brake Switch on H-Relay is faulty. And/or Beta: The wire "a<->4" is faulty. And/or Gamma***: The Make and Brake Switch on SB2-Relay is faulty. And/or Delta: The wire "3<->2" is faulty. And/or Epsilon***: The Normally Closed Switch on QB-Relay is faulty.

The next tessst I would do is to jumper "a<->1" (or "b<->1" if "a" is hard to get at). If (if) NOW You do NOT have "action on the playfield": The fault (one fault) MUST be in/at Make and Brake Switch on H-Relay. MAYBE the H-Relay is not pulling (?) - this "part of the switch is entitled to stay open". Maybe the H-Relay is pulling - but the "Make Part" of the Switch is faulty ? Have a close look at the relay (pulling ?) an the switch (contacts clean ? / having contact ? / wires soldered-on ?)

If (if) the result of tessst is: You do have "action on the playfield": Make
testtt: Jumper "a<->2" (maybe "b<->2") - Do think about the result as described in explanation "tessst".

You can do many jumperings, example: "a<->4": You test "wire RED-YEL" - is the metal wire inside the insulation broken somewhere ? Just proceed using the result of testtt.

Another problem: "Flippers buzz and machine-gun": When You push the flipper button ? Or "without pushing the flipper button" ? How about bumpers on the playfield / "switches on the playfield activating Score-Reels" ?
Greetings Rolf

P.S.: Alfa***, Gamma***, Epsilon***: When the RELAY is "faulty-pulling" (or "faulty-not-pulling"): The switch on this relay is good - he / it is entitled "to be open" (or "to be closed").
aGtb-Duotron-pinside-JPG-03.jpg

Connect one lead to one side of the switch, and the other lead to the other side of the switch.

Truly bad relays won't energize and trip, which can cause problems, but if tripped manually it won't matter.

So at this point you know it works if you go from H to the far side of QB. The goal is to isolate where within that path the open exists.

To do that, you want to progressively jumper over fewer things until it doesn't work again, and then the last thing that was let into the path is where the problem exists.

so you could jumper from H to the near side of QB. And then from H to the far side of SB, and then from H to the near side of SB. Each time you'd be letting one switch back into the path.

Or, you could quite literally jumper one switch at a time (QB, SB, or H), which would force that switch closed. If one of those makes it work, then that's where the problem lies.

The goal in using the jumper is just to eliminate variables, until the location is isolated.

red-yel and red-wh.

yes, find the red+wh wire on one switch blade of QB, and then the other switch blade that makes the pair is the other one you want. For SB, find the make/break switch (i.e., it has three blades), locate one of the colors to identify it, and then use that to identify the other blades.

SB2 is the relay on the very end (labeled Reset Control Relay). Is that the one you're working on? That's the one called out on the schematic. (I was using "SB" generically before, sorry if that wasn't clear.)

Looks like the make/break switch is on the taller of the two switch stacks, on top (so the right side stack as in the picture).

Looks like the make/break switch on SB2 has had some work done to it before (top switch solder looks modified). It's that top make/break switch that needs to function, so I'd still concentrate there (including jumpering from there to QB).