(Topic ID: 214478)

Playfield suddenly went dead


By jaybird5619

1 year ago



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  • 46 posts
  • 9 Pinsiders participating
  • Latest reply 1 year ago by MarkG
  • Topic is favorited by 1 Pinsider

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Target Alpha score control relays 3 (resized).jpg
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Target Alpha add player unit (resized).jpg

#1 1 year ago

The playfield of my Target Alpha suddenly went dead. No lights, flippers, pop bumpers, rollovers, etc. The machine powers up, backbox lights up, score reels reset, drop targets reset, and the ball kicks out. But that's it -- not even GI lights on PF. I checked the 4 fuses on the bottom panel and 3 fuses under the PF-- all are good.

Some background: This is a project I've been working on for about a month now. With the help of several forum members, I got it running fine a couple of weeks ago. Since the, I've been in the process of rebuilding the pop bumpers and flippers, etc. I finally got them all reinstalled today and turned it on. Initially, one of the pop bumpers was stuck on. I adjusted the EOS switch and that solved the problem -- everything seemed to be working fine. I then replaced a few bad bulbs and reinstalled the chimes. I turned it on again and that when the playfield went dead.

And direction would be greatly appreciated.

#2 1 year ago

Drops reset and ball kicks out so it seems playfield is getting power. Slam tilt switch somewhere? Anything lit in the backbox like tilt or game over?

#3 1 year ago

Could have a shorted socket go back over the light you last changed out. I would also unplug the chimes.

Now that I think about it remove the bulbs you installed and unplug the chimes see if that gets you back to where you were. Then go from there.

#4 1 year ago

Check fuses first, then check tilt and game over relays. They both have switches which control power to the playfield.

#5 1 year ago

Thanks for the suggestions. I'll be back on it in the a.m. and will give an update.

#6 1 year ago

What's the Tilt Hold (H) relay doing?

#7 1 year ago

I've posted a short video that shows what's happening when I start up the machine.

HowardR -- The Tilt Hold (H) relay engages when I press the replay button. It stays engaged until the ball is ejected and then de-energizes. NOTE: if I manually hold the relay in, the playfield operates (lights, flippers).

Here's a play-by-play of the video:

Turn on pin:
- Q relay engages (and no other relays)
- Backbox lights illuminate

Press replay:
- Drop targets reset
- Score reels reset
- Ball ejects
- Playfield lights illuminate, but then go off as soon as score reels reset and ball ejects
- Player 1 score reel lights illuminate, but then alternate between player 1 and 4 (even though no additional players were added).
- No playfield scoring of any kind, no flippers, pop bumpers, kickers, etc.

One thing I find strange -- the bonus unit sure seems to be making a lot noise -- not sure why it would be doing that, since there's no scoring taking place.

#8 1 year ago

Does the Tilt (T) relay engage when the Tilt Hold (H) relay deenergizes?

#9 1 year ago

only for a milisecond. when H deenergizes, I see the tiniest bit of movement (and small spark) on T, but T does not stay engaged.

#10 1 year ago

Check all the tilt switches. One of them is energizing the Tilt (T) relay which then deenergizes the Tilt Hold (H) relay.

#11 1 year ago

The video shows the game going back and forth between player 1 and player 4. For that issue I'd suspect either the coin unit or the switches shown in the red box:

Target Alpha add player unit (resized).jpg

The P/Add Player Unit relay fires when the ball rolls over the trough switch and stays active through an entire score motor cycle (1/3 turn or 120 degrees). In that cycle the coin unit determines how many pulses the Add Player Unit solenoid gets (1-4). I seems to be getting 3 of the 4 it needs to get back to player 1 so most of those switches seem to be working. The P2G, P3G and P4G switches are on the Player Unit.

/Mark

#12 1 year ago

Gents -- thanks! Almost there.

HowardR -- right you were on the tilt switches. A previous owner had disconnected the tilt pendulum and the loose contact was touching the back of the switch stack. Now the playfield lights up and everything works .... except ....

NEW ISSUE: the player 1 thousands reel won't stop. I understand that this typically means a rollover or other FP feature switch is stuck on, or that the preceding score reel (in this case the 100's) switches are out of whack. I'm not exaggerating when I tell you I've been over every PF switch - including all 15 drop targets and player 1 score reels - at least 10 times and cannot find anything. Is there someplace else I need to look?

Thanks again for all your help.

#13 1 year ago
Quoted from jaybird5619:

the player 1 thousands reel won't stop.

In what context? During reset, or once the game has started playing? And is the score motor turning at the same time?
Unless the M/100pt relay (and the 100s score reel) are firing, it's unlikely to be a carry from the 100s score reel.

/Mark

#14 1 year ago

Score reels reset and then immediately the thousands reel starts up. Score motor runs continuously

#15 1 year ago

Check the 9s switch on the 100s score reel. It's making contact and the 1000s reel is thinking it's supposed to increase.

#16 1 year ago
Quoted from jaybird5619:

Score reels reset and then immediately the thousands reel starts up. Score motor runs continuously

Does it ever kick out the 1st ball? It could be that the game is stuck in reset. If you add a non-zero score to all 4 players and then start a new game, does it ever get to resetting players 3 and 4?

If not, the runout switch on the errant score reel could be stuck closed so the reset circuit never sees it in the zero position. The score motor keeps pumping out pulses waiting for all the score reels to arrive at zero but one never does. The runout switch on the player 1 1000s score reel has a brown-red wire on both sides (which is a little unusual).

Have a close look at a working score reel. The runout switch is the one that opens when the reel shows zero. Then have a look at the same switch on the bad reel. Does it open the same way? Or is it shorted somehow? Sometimes if the score reel has been disassembled, the cam follower isn't put back just right between the various switches.

/Mark

#17 1 year ago
Quoted from MarkG:

Does it ever kick out the 1st ball?

Yes, ball kicks out.

Quoted from MarkG:

If you add a non-zero score to all 4 players and then start a new game, does it ever get to resetting players 3 and 4?

Yes, all 4 sets of reels reset to zero.

Quoted from MarkG:

Have a close look at a working score reel. The runout switch is the one that opens when the reel shows zero. Then have a look at the same switch on the bad reel. Does it open the same way?

The bad reel has 3 sets of switches in the stack. They open/close the same as other reels as follows, top to bottom:
0 position: Open/Open/Closed
1-8 position: Open/Closed/Open
9 position: Closed/Closed/Open

Here's a shot of the errant reel in the "0" position.

IMG_0046 (resized).JPG

#18 1 year ago
Quoted from jaybird5619:

Score reels reset and then immediately the thousands reel starts up. Score motor runs continuously

If the 1000 Point relay is pulsing, narrow down on the problem by putting slips of paper in the various circuits that can drive it.

Pinball (resized).png

#19 1 year ago

I'm curious what would cause the score motor to turn.
Target Alpha score motor (resized).jpg
Are either of the Score Control relays (C or D) firing?

#20 1 year ago

D pulses, C does not.

#21 1 year ago

OK, I'm an idiot. It's the 100s reel (not 1,000s) that's acting up. Not sure if that even makes a difference, but just so we're all on the same page. I carefully checked the switches on the 100s and 10s, and they both look good.

#22 1 year ago
Quoted from jaybird5619:

D pulses, C does not.

Ok, it probably shouldn't be.
Target Alpha score control relays 2 (resized).jpg
With the power off, can you check the resistance (not the continuity) between the white-orange wire on the solder lug of the D/Score Control relay and the orange-black wire on the other side of any of the rollover switches on the top half of this schematic? You should see a very high resistance but at least 10 ohms or more. A stuck closed switch (or a short) among those rollovers could explain why the score motor is running.

If your game is in 3 ball mode and adjusted for 500 points per target also measure the resistance between the maroon-yellow wire and the blue-black wire (not labeled) on the other side of any of the drop target switches.

#23 1 year ago

For clarification, when you say that the 100pt reel keeps running, is it adding 100 points at a time (like a pop bumper might) or 500 points at a time (like a rollover might)? You can tell the difference by listening to it. If there is a constant delay between each 100 points you're adding 100 points. If there is a group of five, then a slightly longer delay then another group of 5, you're adding 500 points.

100 and 500 (or 10 and 50, or 1000 and 5000) use slightly different relays and circuits but the big difference is that usually 100 (or 10, or 1000) does not start the score motor while 500 (or 50 or 5000) needs to start the score motor to generate the 5 pulses needed to advance the score reel 5 times.

#24 1 year ago

HowardR -- resistance between White/Orange lug on D and any of the upper rollover switches is .06-.07 ohms. On the drop targets, I did not get any reading (other than the DMM default reading of "1" (with DMM set to 200 ohm). Maybe I'm doing something wrong? Also, wires on my machine are very faded -- I'm assuming the yellowish wire feeding the end of each drop target bank is the yellow/maroon. Blue/Black was very clear.

MarkG -- the reel is definitely adding 500 pts at a time. It's only a very brief pause between the sets of five, but it's quite clear.

As I'm sure both of you can tell, I'm pretty new to all this. I've replaced a few parts on a couple of machines, but this is my first full-on project with a non-running machine. I'm struggling to make sense of the schematics, but am determined to so as I know that's the secret to understanding all this. So, any guidance with the schematics is much appreciated.

Jay

#25 1 year ago
Quoted from HowardR:

If the 1000 Point relay is pulsing, narrow down on the problem by putting slips of paper in the various circuits that can drive it.

Quoted from jaybird5619:

HowardR -- resistance between White/Orange lug on D and any of the upper rollover switches is .06-.07 ohms. On the drop targets, I did not get any reading (other than the DMM default reading of "1" (with DMM set to 200 ohm). Maybe I'm doing something wrong? Also, wires on my machine are very faded -- I'm assuming the yellowish wire feeding the end of each drop target bank is the yellow/maroon. Blue/Black was very clear.

Quoted from jaybird5619:

It's the 100s reel (not 1,000s) that's acting up.

If the 100 Point relay is pulsing, narrow down on the problem by putting slips of paper in the various circuits that can drive it.

#26 1 year ago
Quoted from jaybird5619:

resistance between White/Orange lug on D and any of the upper rollover switches is .06-.07 ohms.

Assuming you're not measuring the resistance from one end of the white-orange wire (on the relay) and the other end of the same wire (on a rollover switch) and this is really the reading you're getting between the white-orange and orange-black wires on either side of the rollover switches, that is your problem. Either one is stuck closed or there's a short elsewhere but the game sees a 500 point target closed all the time.

#27 1 year ago

On a Target Alpha, as I recall, the only 500 point switches are all lane rollovers. If it is continuously scoring 500 points over and over, I would look at those switches very carefully. I would bet one of them is shorted somehow.

#28 1 year ago

I inserted pieces of index card between the switches on every rollover (as well as the 2 bulls eye targets and the switches behind the rubbers) -- same result --100's reel keeps rolling. I also very closely examined the back of each switch stack to make sure no issues there. In fact, I've examined every solder joint in the entire machine and I don't see anything lose or shorting.

One interesting note. In the process of inserting the cards, on ONE occasion, I turned on the machine, hit replay, it reset and the 100s score reel did NOT continue to turn, but the score motor did continued to run. I immediately powered down and re-started, and it was back to usual (score reel running).

Question: since I've never actually had this machine running, how many points should the drop targets give as you hit them (not on bonus at EOB).

I'm getting extremely frustrated. Any other thoughts on how to go about trouble shooting?

#29 1 year ago

Is it scoring 500 at a time (100-200-300-400-500-pause), or 100 at a time smoothly?

#30 1 year ago

Sounds like 500 at a clip to me, but you can take a listen...

#31 1 year ago
Quoted from jaybird5619:

I inserted pieces of index card between the switches on every rollover (as well as the 2 bulls eye targets and the switches behind the rubbers) -- same result --100's reel keeps rolling

What is the resistance across any of the rollover switches (shown in the top half of the schematic in reply #22) from the white-orange wire to the orange-black wire? I thought you said the resistance was < 1 ohm:

Quoted from jaybird5619:

resistance between White/Orange lug on D and any of the upper rollover switches is .06-.07 ohms.

To phrase it another way, does the resistance across the switch change as the switch opens and closes? If you measure < 1 ohm across those switches you'll see the constant "add 500 points" behavior you're seeing because the D/Score Control relay fires, paper between the switch contacts notwithstanding.

Quoted from jaybird5619:

Question: since I've never actually had this machine running, how many points should the drop targets give as you hit them (not on bonus at EOB).

If you look at the schematic in reply #22 in the bottom left is an adjustment for the drop target value. In a 5 ball game the targets are worth 2000 points. In a 3 ball game you can make them worth either 500 or 2000 points based on the position of the jones plug adjustment.

#32 1 year ago

I just re-tested the 8 rollovers listed in #22. Did it 2 ways: 1) from white-orange lug on D to the orange-black on the switch and 2) from the white-orange to orange-black on the switch itself (not sure if this makes any difference, results are the same).

For all switches I got (with my DMM set at 200 ohms) between 0.6 to 1.0 with switches open. When I closed switches, they would sometimes drop by 0.1-0.2 ohms, sometimes no change.

Just fyi, all test have been conducted with pin set to 5 balls.

#33 1 year ago
Quoted from jaybird5619:

For all switches I got (with my DMM set at 200 ohms) between 0.6 to 1.0 with switches open. When I closed switches, they would sometimes drop by 0.1-0.2 ohms, sometimes no change.

This is why the D relay stays on and the game constantly adds 500 points at a time. There's a short somewhere between those two wires that keeps the relay on. You should see at least a 5-10 ohm difference between the open and closed positions of a switch.

At this point I'd shut off the power, clip the meter leads to both sides of one of those switches and start tracing the wires, poking around and see if you can wiggle things to get that resistance over 5-10 ohms to help you find that short.

If the D relay is on the bottom of the cabinet, you might try unplugging the jones plugs that connect the playfield to the cabinet. That might tell you if the short is on the playfield or in the cabinet.

#34 1 year ago

I’ve disconnected the play field from the cabinet. Still getting 0.6 from the PF switches. Does that that mean problem is on the PF?

#35 1 year ago
Quoted from jaybird5619:

I’ve disconnected the play field from the cabinet. Still getting 0.6 from the PF switches. Does that that mean problem is on the PF?

Yes.

As a sanity check, try measuring the resistance across a few unrelated playfield switches (open and closed) to convince yourself that you can recognize the change in resistance of a working switch with your meter.

#36 1 year ago

I'm clearly doing something wrong. I measured the resistance of the 2 standup targets. I attached the meter leads to the leads of the switch (photo 1). It measured "1" (photo 2). I closed the switch (photo 3) and it measured "0.4" (photo 4). Meter is set on 200 ohms.

IMG_0050 (resized).JPG

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#37 1 year ago

Looks set right and leads correctly in the meter.

When you touch the leads of the meter together does it read zero? Do you have any known value resistors on hand you can test? New coils on hand maybe?

#38 1 year ago

When I touch leads - get 0.2 to 0.3. I have a used Williams FL-17636 coil that measures 77ohms on the left-right and left-middle lugs.

#39 1 year ago

FL-17636 WILLIAMS FAT 4R3/384R

Should measure 4.3 on the primary coil and 38.4 on the hold windings. Something wrong with your meter.

Edit: check coil again with leads reversed. Could be a diode built - in.

#40 1 year ago

It must be a bad coil .. can't remember why I kept it. I'm getting 3.0 on the primary -- no matter which order I have the leads.

#41 1 year ago
Quoted from jaybird5619:

I'm clearly doing something wrong. I measured the resistance of the 2 standup targets. I attached the meter leads to the leads of the switch (photo 1). It measured "1" (photo 2). I closed the switch (photo 3) and it measured "0.4" (photo 4). Meter is set on 200 ohms.

I think your meter is working fine. The "1" you're measuring I think is actually "open circuit", which is what I would expect for an open switch. A 1 ohm measurement would likely be right justified and show something like 1.0. If you disconnect the leads from anything I bet the meter still shows a left justified "1".

So the switch you show goes from open circuit to less than an ohm as you open and close it which is what you want. Sometimes there is actually an electrical path between the two sides of the switch that passes through other coils. In that case you won't get a "1" or open circuit, but some higher resistance value (generally 5 ohms or more). But when you close the switch, any switch, you should read something less than 1 ohm or so.

To make these measurements you need to use the lowest resistance setting on you meter (which you are) and not the continuity setting because if there is another path between the two sides of the switch a continuity test won't be able to distinguish between the path through a closed switch and the path through the other coils.

#42 1 year ago

MarkG -- you are correct: with the meter set to 200 ohms (lowest setting) and not connected to anything, I get a left-justified "1". And as you note, when I close a switch (rollover, standup target, etc.), I do get a very slight drop, usually around 0.2 ohms.

All that being said -- not sure where that leaves me with my issue. Because I'm getting that slight change on the playfield, which I've disconnected from the cabinet and which contains relay D, does that rule the PF out? If so, I'm not sure I understand how to test the cabinet wiring. I'm assuming I connect to the orange-white lug on D but not sure what I'm connecting to from there.

Thanks again, everybody.

#43 1 year ago
Quoted from jaybird5619:

with the meter set to 200 ohms (lowest setting) and not connected to anything, I get a left-justified "1". And as you note, when I close a switch (rollover, standup target, etc.), I do get a very slight drop, usually around 0.2 ohms.

To clarify, the left justified "1" is not one ohm, but effectively infinite ohms. So the drop to 0.2 ohms is from infinity to less than one, which is a huge drop.

Quoted from jaybird5619:

not sure where that leaves me with my issue. Because I'm getting that slight change on the playfield, which I've disconnected from the cabinet and which contains relay D, does that rule the PF out? If so, I'm not sure I understand how to test the cabinet wiring. I'm assuming I connect to the orange-white lug on D but not sure what I'm connecting to from there.

Since you've disconnected the playfield jones plugs the cabinet and playfield are no longer connected - they're electrically isolated from eachother.
Target Alpha score control relays 3 (resized).jpg
The D relay and score motor switches are in the cabinet, and the rollover switches are on the playfield. With the jones plugs disconnected you're left with the circuit inside the red box. In reply #34 you said that you disconnected the playfield jones plugs and measured less than an ohm between the white-orange wire and the orange-black wire on the playfield. (You should see the same value on any of the 8 rollover switches since they're all wired in parallel.)

What you should see is an open circuit (left justified "1") unless you close one of the rollover switches, like you did on the standup targets in reply #36.

So do you still see less than an ohm between the white-orange and orange-black wires on the playfield regardless of whether the rollover switches are open or closed? If so, that's a problem somewhere on the playfield.

#44 1 year ago

Sorry I can't add anything to the troubleshooting, but I have to say it is amazing to see this level of help from the community. I'm learning quite a bit about the troubleshooting method with EMs. Good luck to you OP.

#45 1 year ago

SUCCESS! The problem was the leaf spring between the leaves of one of the rollovers. It was making contact with the leaf above it. I looked 50 times at the contacts on this switch, but was overlooking the spring leaf. A little tweak and no more run-away score reel!

a HUGE thank-you to everyone above, especially MarkG and HowardR, who patiently and persistently stayed with me until the problem was solved.

Javaman -- I couldn't agree more. I could have never got this machine up and running without the support of members of this Forum -- it was a tremendous learning experience --- just hope I can pay it forward some day.

Thanks again to all of you.

#46 1 year ago
Quoted from jaybird5619:

just hope I can pay it forward some day.

That's the ticket.

I hope the success outweighed the frustration. It usually does for me.

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