*** PROBLEM RESOLUTION COMPLETE, SUMMARY EDIT (because this thread got lonnnnng):
*** Turns out there was a whole assortment of problems, which is why it took so long to get there. Still, I had superb help from fredsmythson and woz, and a short summary of the problems were:
*** AB / AB-reset switches adjustment required
*** Assorted switch adjustments required on P, Q, O relays
*** Ball stepper Ball 1+ switch adjustment required -- properly tell machine it's moved from 0 ball to 1+ ball position
*** Ball stepper spring adjustment required -- help along the stepper
*** Ball stepper Ball 6 switch adjustment required -- when closed, sends power to O, P, Q relays
*** W relay switch adjustment require (red/white wire and green/yellow wire) -- in circuit which sends power to kicker
***END OF SUMMARY , original post below.

Reference this previous thread (https://pinside.com/pinball/forum/topic/1973-gottlieb-pro-football-score-reel-broken-eos-leg) for history thus far.

I have a 1973 Gottlieb Pro-Football I snagged as a "storage-find" and have been working to bring it back to life. I tore down and cleaned all the score reels, the credit stepper, and the ball stepper. It's acting glitchy during my attempts to start it, however.

I seem to be having issues with the ABR actuation. Per that previous thread, newmantjn mentioned that ABR actuation is triggered by the following: ALL the runout switches need to be closed, AND the ball count unit needs to be at Zero AND the motor 4D switch needs to close properly.

- I've verified the ball stepper resets to zero.
- I've verified the motor 4D switch makes good contact.
- I've verified all my reels reset to zero and switches make good contact.

So here's what actually happens, which is what's confusing me:

** Scenario A: If any of the reels have any score (other than zero) on them, and I hit the start button, the credits decrease by one, the ball stepper resets to zero, and the applicable reel(s) will reset to zero ... but the motor keeps running, and ABR does not actuate.

** Scenario B: If all of the reels are ALREADY at zero (untouched by human hands since the last reset!), and I hit the start button, the credits decrease by one, the ball stepper resets to zero, and the ABR DOES actuate after the motor 4D switch makes contact (and the motor stops like it should).

I'm not convinced everything is hunky dory even in Scenario B, though ... because the next step described in the manual's operating instructions doesn't seem to work. ("Place the ball in the outhole. When the ball closes the ball return switch, Q relay is actuated ... etc." -- but if I manually close that outhole switch, nothing happens.) One thing at a time though; need to get to this point consistently first.

Thanks in advance for any help.

Crap, I think it might be the ABR coil itself. It stopped doing Scenario B (above) consistently, and so I began to suspect. I checked the resistance across AB (~15) and then across ABR (~9) ... but they're both A-3891 coils, which Pinmedic's coil chart (ref http://www.pinballmedic.net/coil_chart.html) says should be ~15.

Looking back at my notes from months ago when I first got this machine, (and had a little time to glance it over but not much else) it looks like I'd checked all the coils -- but without the schematics so I didn't know what should be what. Apparently it was just a cursory check to see if anything jumped out (e.g., zero resistance). Now that I have the schematic, it appears I have about seven dying coils in here:
A - A-9740 - Alternating Relay - s/b 22 Ohms, is 9.
E - A-9735 - 10 yd & 100 score Relay - s/b 15 Ohms, is 9.
J - A-489 - 00-90 unit Relay - s/b 15 Ohms, is 6.
ABR - A-9735 - Reset completed Relay - s/b 15 Ohms, is 9.
Also, A-9740 - Vari-target reset coils - s/b 22 Ohms, is 12. (Two of these, doh.)
Also, A-7677 - Coin lockout coil - s/b 25 Ohms, is 1. (I don't care about this one though, I know this one is unnecessary for home machines)
Also, A-9154 - Scoring unit coil - All are ~6 Ohms, except one ~4. They all work though (as shown during reset cycle), so I'm not sure if I should replace this one.

Alright, new coils ordered. More to follow once I receive and install them.

(I guess I really ought to wait for replies before I go off buying parts, lol ... darn ants in the pants.) No, my tests were performed with leads connected. Can/does this make a difference, why and how?

I don't know the answer to that question -- but (speculation here) perhaps it's not quite that simple in this case, because the AB and ABR "interact" with little plates that hold/release each other, and they only have a split second to do it, as triggered by the momentary contact at the Motor 4D closure. If one coil is "starting" to die, could its response time be slightly slower? If so, perhaps this is why the cycle would only intermittently complete / stop.

Then again, maybe it's all confirmation bias -- being pretty confident everything else was fine, I was looking for a problem with ABR, and "found" one in its lower resistance.

I would imagine in most cases where each coil stands alone, "it works or it doesn't work" is probably true, because its overall function isn't dependent on the the relative speed of its reaction. (In which case, hopefully I won't have to replace all those other coils, like you suggested.)

Again, speculation / assumption / educated guess. Remember, I'm still somewhat of a beginner at this.

It appeared to be the only thing left that seemed to make sense. Here is the snippet from the schematic. For this part of the cycle to be complete, all the reels have to be at zero (confirmed), the ball stepper has to be at zero (confirmed), and the Motor 4D has to close (confirmed, closing the switch momentarily as it the motor turns). When all of these conditions coexist, the AB/ABR action should occur to complete this portion of the startup cycle.

schematic_(resized).png

Now that I've already ordered all the parts, I may at well start with the ABR one and see if that makes any difference. It'll be a few days until they get here, though, so I am -- and always will be -- all ears.

No; it's a single player game.

Ok, I'm re-looking at this again. First things first: I had the two coils mixed up in my mind -- it's the AB coil that has the low(er) resistance, and that one is operating just fine. The ABR coil, which has good resistance, doesn't appear to be actuating -- which must mean that something's not telling it to.

-- I just checked the reel switches again, no resistance across the zero switches when the reels are at zero. All the reels reset to zero during startup.

-- I visually verified the 4D switch is closing when it the motor rotates that peg through. The switch it closes definitely makes hard contact, and you can occasionally see the spark as they do so.

-- So maybe I should be suspecting the ball stepper? The startup sequence definitely triggers it to reset to zero position. But, once it's there, which switch(es) tell the machine it is there? Here are some pics of my ball stepper at zero position, please tell me if this all looks kosher:

ballstepper1_(resized).jpg
ballstepper2_(resized).jpg
ballstepper3_(resized).jpg
ballstepper4_(resized).jpg
ballstepper6_(resized).jpg
Here's a look with it pulled down, to see the switches on the back.

The manual says once all the reels and the ball stepper are at zero, the ABR coil should actuate -- which would open the switch to stop the motor.

Thanks, just checked it, zero resistance.

Argh, what am I missing?

I was measuring Ohms, and was getting big fat 0s as I should. Just for good measure (ha, see what I did there?), I took a quick minute this morning and dropped the DMM over to Continuity mode and checked again all six score reels Zero switch, and the ball stepper terminals indicated by woz (above) and got a good beep at each one.

Since my pinball area is also my cats' domain, and I don't trust them with an open machine, I'd closed/reassembled the lower cabinet last night and thus I didn't have time to attempt it this morning. Will see if I can find some time over the weekend -- though some upcoming priorities may pull me off this machine for a while. Stay tuned...

Thanks for all the help thus far.

1) Ok, checked continuity per your instructions -- results: good beep.
2) Tried jumping. I'm not sure which to jump from on the transformer -- probably the black one that then goes to the primary fuse? I jumped from this terminal on the transformer to either terminal on the coil, and nothing happens.

Fantastic recommendation -- another great testing tip to add to my bag o' tricks. I've completed this test and the results are interesting -- check out this video:

I cleaned the plate on the AB coil -- there was a little gunk on it -- just to be sure that wasn't restraining the ABR plate. After cleaning it, the results are the same. Is this ABR coil just dying? It just seems like it's not pulling hard enough.

Yes, the ABR actuation does stop the motor. See photo below -- I manually close the switch circled in green, the motor runs. Also, the switch circled in green actuates the Z coil in the backbox, which allows the score reels to be reset.

abr-notes_(resized).jpg

I haven't yet figured out what the 'top' one does when it closes, nor the 'bottom' one when it opens, because nothing seems to happen when they're open/closed manually. Probably dependent on some other open/closed condition elsewhere ...

Alright, so I don't know what changed. I've been going around checking other stuff related to the startup sequence (e.g., Start relay), checking continuity where it should & shouldn't be on the open/closed switches, and now the ABR seems to be working reliably -- every time I run the cycle from the Start button or by manually activating the Start relay, it completes the cycle and the ABR relay actuates when it should. Maybe all the fiddling with the AB/ABR, or the start relay, or who knows what .... I'm hesitant to called the ABR issue solved, but it seems to be functioning fine right now.

Even more evidence that I'm on the right track: It allows the next step in the process to try to work. Naturally, I've got a problem here too.

Per the manual, once the reset cycle is complete -- which it is -- the next step in the process is:

Manual: "Place the ball in the outhole. When the ball closes the ball return switch, Q relay is actuated, a switch closes and pulls in P relay thru normally closed on O relay and motor 1C."
What I have: This does appear to happen -- I manually close the ball return switch, Q actuates, P actuates.

Manual: "When P relay pulls in the motor starts running."
What I have: While P is pulled in, motor runs.

Manual: "The normally open switches on P relay close, completing the circuit to O relay and the add ballcount unit coil thru motor 4C switch."
What I have: This doesn't seem to be happening well. O relay stutters and releases, and nothing happens at the ball relay.

Manual: "O relay stays locked in thru its own switch and normally closed switches on L, M, and N relays".
What I have: Again, this doesn't happen, because O relay does not stay locked in. If I manually push the O relay open further, it locks open but makes a horrible buzzing sound. The motor stops, and relay P releases.

Lots of questions. Ok -- first, I should note that a switch in the credit stepper has been bent to allow free play, as has been shown in other pinball guides. So, even with no credits on the the credit unit, it still allows the start button to start a game.

If I shut the game off and turn it back on by the switch under the cabinet, it always turns back on with the Tilt light on. I have not seen the Game Over light come on, well, ever, since I've never gotten that far.

When I press the start button:
- The R coil (hold relay) actuates and stays that way.
- The S coil (start relay) closes for a moment to initiate the startup sequence, then releases.
- The AB relay pulls in, the motor starts to turn.
- If there are credits on the credit unit, they decrease by 1. (If there are none, it starts anyway due to the 'free play' adjustment made to the switch in the credit stepper.)
- If the ball stepper unit is on anything but zero, it drops to zero position.
- If the score reels have anything but zero, they reset to zero.
- If the "I" relay (yard stepper) is not at zero, it resets to zero.
- Once all of these are complete, the ABR relay pulls in and the motor stops.
According to the manual, this means the first part of the startup sequence is complete.
(Which would then bring us back to my previous post.)

Ok, another video to help show where I'm at.

Things to note before you watch it:
1) I repeatedly referred to the P coil/relay as R. I realized it late in the video. Q, P, and O are in a line. It's not Q, R, and O as I mentioned.
2) I pointed out the ball stepper, because I advanced it just to show it worked. I didn't go around (in the video) to prove that it worked and returned to zero position -- but it did.
3) As you'll see, after running the startup cycle with the playfield down, it gets to a point where it *appears* it's ready to play. It's not, though -- it didn't attempted the next part of the cycle, which would have pulled in Q, P, then O, and should also bump the ball stepper I think.

Here's the video.

I've been playing around with it some more with the ball in the outhole, and it only SOMETIMES gets as far as the "buzzing O" as I'll call it. All kinds of strangeness can happen after that -- sometimes I manually throw the ball stepper actuator, the score motor turns briefly, I get buzzing O again, and THEN IT ACTUALLY LETS ME LAUNCH A BALL AND PLAY. After the ball drains, the ball stepper still doesn't advance, but it would let me launch again. Each time the ball drained, the ball stepper still wouldn't advance, so something's definitely not happening up there the way it should, or something's not allowing it to. Also, what do you think might be causing the buzzing?

Crap, you're right -- here's the proper link:

(I'll go back and edit the previous post to put the right vid there for others reading along.)

No, there is only one switch here -- it tells the machine there's a ball in the outhole. You can see it sticking into the lane next to the shooter. I did clean the contacts and verify it's adjust properly. See photo:

outhole_(resized).jpg

FYI, per this other thread (https://pinside.com/pinball/forum/topic/1973-gottlieb-pro-football-ball-in-play-skips), it sounds like it's the P relay that should trigger the ball stepper. I'll be taking a closer look at that next time I have a moment.

Ball shooter doesn't come into play until the next step of the process, according to the manual. So, focusing on Q, P, and O, here's what I came up with:

I checked continuity on the relay switches for Q, P, and O, and came up with three things out of the ordinary -- one switch on P, which is normally open, still has continuity (even when open), and I don't really understand why. On Q, one that is normally open still has continuity, and one that is normally closed, once opened, still has continuity. See photos below.

P relay

Q relay note 1

Q relay note 2

Please note: Unfortunately I'm going to be slammed the next two weeks and really won't have time to touch this machine. I look forward to any assistance / suggestions you all can provide, and when the insanity subsides, I'll try out your recommendations and see where we get.

The latter is what I suspected, but your idea to disconnect them is a good way to be sure. Thanks again. We'll get there....

I've checked and re-checked to make sure they're not touching. The photo's a little deceiving for a few of them, just because of the angle of the shot.

I've hit most of them with the flexstone but going back over them again can't hurt.

Yeah I didn't take a shot of the O relay because all of its switches had proper continuity when closed. I can post one at a later time if it'll help.

Thanks, figured it might be more helpful than just pics. I presume you're referring to the longer, startup demo video -- and I also presume you mean it doesn't fill the screen width ... that's because I shot it with my phone oriented vertically, to better capture everything in the picture at once without having to turn your head sideways.

No it is not. I have not witnessed the ball count unit advance up on its own, ever. The coil measures good resistance, though. (Note, wires attached to terminals.)

In tinkering with it over the weekend, I did get this to work a few times. I got to the point in my video where the O coil was locked in (and buzzing horribly), and I manually advanced the ball stepper ... something cycled, and I got the buzzing O again, but then pushing the flipper actually launched the ball and the game would play. When the ball drained, the stepper would still not advance (it'd stay on the current ball number) but would allow me to launch and play again.

Note, it didn't allow this consistently. Sometimes I'd get to the buzzing O, manually cycle the stepper, then nothing would happen.

Now it seems I can't even get to the buzzing O consistently. I can hit start and get all the resets completed every time. But now only SOMETIMES will it run the Q/P/O sequence when I close the ball-in-the-outhole switch. Other times, nothing happens.

Such a tease...

When the game is sitting at the end of the first part of startup (after ABR actuates), manually activating the P relay causes the score motor to turn 1/3 turn, and nothing else appears to happen. Ball stepper does not advance.

(FYI, also, when the game is sitting there with 'Tilt' activated, the same thing happens when I manually activate the P relay.)

Interestingly, when I get the startup as far as the "Buzzing O" (with outhole switch closes), if I then manually activate the P relay, the motor turns 1/3 turn, the outhole kicker kicks, and still nothing happens with the stepper.

Since this was a quick check, I did this, as shown in the photo ... though I'd argue the 6th position wire is red/black, not red/green (the 5th looks red/green).

Anyway, after hooking up this jumper, I hit the start button, and the coil retracted the rod. Of course, it stayed there till I cut the power, at which point it completed the cycle and advanced one step. So, stepper coil appears to be good.

20160301_200831_(resized).jpg

MAJOR PROGRESS thanks to you guys!!! I went back and thoroughly cleaned the applicable switches. I also made sure I had continuity from the P switch to the motor 4C switch, and from the P switch to the ball stepper. While I had the P relay removed off the bracket (for better cleaning access), I examined the applicable switch closely and FIRMLY manually cycled it -- and that kicked the ball stepper up one!!! So, I made an adjustment to the switch to ensure it's making better contact, and now it cycles the ball stepper!!!

Now, though, the motor's not cutting off during the Q/P/O cycle. I'll tinker some more, but we're almost there!!! (Also, before I got this far, my switch cleanup now reliably allowed me get to the ball launch & play phase after I manually cycled the ball stepper.)

Ref previous post; here's where I'm at:

Ok FINALLY getting back to this machine.

I did some troubleshooting with the two lines there that trigger the O relay.

Test 1) I hit Start to get the AB relay in the proper configuration. If I then manually close the switch on Motor 4C with the brown/black wire, and also manually close the switch on P with the brown/black wire, it triggers O, which stays locked on when I release the switches (since O has a switch which, when closed, leaves O locked on).

Test 2) I hit Start to get the AB relay in the proper configuration. If I manually close the switch on O with the white wire, it locks O on.

Both of the above tests imply that the contacts on the L, M, or N switches are good -- but I'll verify that too with Test 3.

Test 3) The highlighted line in your last past -- I interpret this (based on what I'm learning at http://tuukan.fliput.net/emkytkis_en.html) as "O stays on until a normally closed switch on L, M, or N is opened". So, I activate O (by either of the methods described in Test 1 & 2), I go around to the backbox, and manually cycle L, and O releases. I repeat with the process twice more but cycle M and N these times, and O releases each time also. This corroborates what the Operating Instructions describe in Steps 4 & 5: "O relay stays locked in thru its own switch and normally closed switches on L M, and N relays. ... When the ball hits a scoring contact, O relay drops out." In other words, when you hit something (which is worth points), the applicable scoring relay L, M, or N would cycle, and would thereby release O.

So ... this appears to mean indicate that the functions should work, but something's not triggering / releasing them properly. I went back and re-cleaned the contacts on the motor switches, just in case, but didn't have much luck there -- the motor still runs and runs (until the ball stepper has stepped through each ball and ends the game). You mentioned the pulse being too short -- how do I adjust this, just by moving the switch contacts closer together, so they're in contact longer?