Bally KNOCKOUT - will not start

http://www.pinrepair.com/em/index3.htm#features

I've been at it for hours, so hoping I can't get steered in the right direction.

Bally Knockout. I don't have the schematic, but I found one for "Amigo" which looks about the same, particularly where I am looking.

I push the credit button, and the coin, credit and reset relays will all trigger. The reset relay will lock on, but score motor will not spin up. The score motor does work - I can get it to spin through a cycle if I activate the "HOLE" relay

I have gone through all the switches, all look to be in their proper state, and cleaned with a dremel wire brush. All the solder joints seem solid, and I can't find anything shorted. I have alligator-clip wires, but I'm not exactly sure how to go about using them to test.

Going through Clay's guide, it looks that the RESET relay should start the score motor.

So, what am I missing, or what should I try next?

-d

#2 6 years ago

HOW

HowardR

Pinside member

Boulder, CO

7y 78,050 6,251

OP
Quoted from songofsixpence:
The reset relay will lock on, but score motor will not spin up.
...
I have alligator-clip wires, but I'm not exactly sure how to go about using them to test.

http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf

#3 6 years ago

???

currieddog

Pinside member

Springfield, MA

7y 63,550 3,312 6

Motor runout sw. on the score motor.

#4 6 years ago

MarkG

OP
Quoted from songofsixpence:
I push the credit button, and the coin, credit and reset relays will all trigger.

Here's a color coded schematic from ipdb.org for Wizard, the next Bally game:

Wizard score motor (resized).jpg

Like yours, it shows that switches on the Coin and Reset relays should both start the score motor. One of them should close the circuit between the white wire and the red-yellow wire to get the score motor started. Since the Credit relay fires, you know the white wire is good. So the problem has to be in either the Reset relay switch or the Coin relay switch, or the wires leading to or from them.

/Mark

#5 6 years ago

DMD

songofsixpence

Quoted from MarkG:
Here's a color coded schematic from ipdb.org for Wizard, the next Bally game:

Like yours, it shows that switches on the Coin and Reset relays should both start the score motor. One of them should close the circuit between the white wire and the red-yellow wire to get the score motor started. Since the Credit relay fires, you know the white wire is good. So the problem has to be in either the Reset relay switch or the Coin relay switch, or the wires leading to or from them.
/Mark

Yeah, that color schematic is nice.
I've looked at the Reset relay switch, and it seems right. I can squeeze an alligator clip into that one, and I get no change.
I'll look at the red-yel wires again

#6 6 years ago

MarkG

If you have a meter, shut the power off and measure the resistance on the lowest range setting between the red-yellow wire on the score motor solder lug and the white wire on any of the relays. Then manually close any of the four switches between the red-yellow wire and the white wire by gently pushing in the relay armature. With any of the four switches closed you should be able to measure just an ohm or two of resistance. You should get about the same measurement from all four switches (closed one at a time). It's possible that the switch is closing as it should but something is preventing it from making a good contact.

#7 6 years ago

DMD

songofsixpence

OK - I get like .3-.4 ohm between the red-yellow wire on the motor, and the white lugs on the relays. No change when I push the relay closed.

#8 6 years ago

MarkG

OP
Quoted from songofsixpence:
OK - I get like .3-.4 ohm between the red-yellow wire on the motor, and the white lugs on the relays. No change when I push the relay closed.

Hmm. What do you measure when you touch the meter probes to each other? If there were really less than 1 ohm between the red-yellow motor lug and the white wire your score motor would run a lot. At least when the Credit relay fires.

#9 6 years ago

DMD

songofsixpence

0.0 - 0.2 when touched together.

For what it's worth, I traced out that white wire. it daisy chains from the RESET to the 2nd COIN CHUTE to the COIN. From there, it doesn't actually connect to anything else. It does connect to the coin door jones plug, but that isn't actually connected to anything

#10 6 years ago

MarkG

The schematics we have may not be right then. Can you trace the circuit from the credit button back towards the white wire? Does it go from blue-orange to black-white to white as shown above?

#11 6 years ago

DMD

songofsixpence

Hmmm not exactly. The blue-orange and Black-white are one off on the jones plug on mine.

My credit button wires look to be pink-black and white-blue

#12 6 years ago

DMD

songofsixpence

For those who prefer a visual, here's a short video

I assume PBR has a schematic for this title. Can probably have it by Thursday.

#13 6 years ago

WFC

Billc479

Pinside+ Frequent

Pleasant Plains, IL

9y 79,800 3,131 15

See if these help.

IMG_3450[1] (resized).JPG

IMG_3449[1] (resized).JPG

IMG_3448[1] (resized).JPG

#14 6 years ago

DMD

songofsixpence

That one is close - but I don't actually have a 3rd coin chute.

I guess my question is where does the white wire connect to the yellow rail?

#15 6 years ago

MarkG

OP
Quoted from songofsixpence:
For those who prefer a visual, here's a short video

Love those lift out playfields...

OP
Quoted from songofsixpence:
That one is close - but I don't actually have a 3rd coin chute.
I guess my question is where does the white wire connect to the yellow rail?

On the schematic from Billc479 above and on the Wizard schematic I used earlier (although not shown in the section I posted) the white wire goes through the normally closed sections of make/break switches on the 2nd and 3rd coin chute relays to the main yellow supply wire.

OP
Quoted from songofsixpence:
Hmmm not exactly. The blue-orange and Black-white are one off on the jones plug on mine.
My credit button wires look to be pink-black and white-blue

Ok, nothing like the schematics we have then.

Have you ever seen this game work? If not we have to assume that it may have been hacked at some point which makes the number of possible problems much greater.

OP
Quoted from songofsixpence:
For what it's worth, I traced out that white wire. it daisy chains from the RESET to the 2nd COIN CHUTE to the COIN. From there, it doesn't actually connect to anything else. It does connect to the coin door jones plug, but that isn't actually connected to anything

This is troubling. If you can trace from the score motor red-yellow wire through the Reset, 2nd Coin and Coin relay switches to the white wire, and the white wire goes nowhere that's a problem. You can get the score motor running by closing the relay switches tied to the yellow wire, but the white wire apparently is floating which it shouldn't be.

#16 6 years ago

DMD

songofsixpence

Quoted from MarkG:
Love those lift out playfields...

Actually, the control board... ? Maybe I should have had a disclaimer "Don't try this at home" but my back thanks me

Quoted from MarkG:
On the schematic from Billc479 above and on the Wizard schematic I used earlier (although not shown in the section I posted) the white wire goes through the normally closed sections of make/break switches on the 2nd and 3rd coin chute relays to the main yellow supply wire.

yes, which makes sense to me. I cannot find any way the white wire connects to the yellow rail at all.
I have thought about adding a switch, and connecting it to the 2nd coin relay, (there is no 3rd coin relay) as pictured in the Amigo and Wizard schematics, but I wonder if there is really something different in the Knockout schematics.

Quoted from MarkG:
Have you ever seen this game work? If not we have to assume that it may have been hacked at some point which makes the number of possible problems much greater.

Negative. and yes there are previous hacks / mods, including credit wheel had been removed.
Then again, there's this:
The Coin Relay has 3 silver wires tied together on one side of the bottom switch. The other side of the switch doesn't seem to have any solder residue, or any other indication it was ever used.
CoinRelay (resized).jpg

Quoted from MarkG:
This is troubling. If you can trace from the score motor red-yellow wire through the Reset, 2nd Coin and Coin relay switches to the white wire, and the white wire goes nowhere that's a problem. You can get the score motor running by closing the relay switches tied to the yellow wire, but the white wire apparently is floating which it shouldn't be.

Yes, we are on the same page.
Also I don't mind if this machine had previous kludges, but I worry most if there were an attempted kludge, that didnt work, before this game headed for retirement in a dusty, old basement.

I am reaching the opinion that the white wire needs to be connected to the yellow through a switch.

#17 6 years ago

MarkG

Yeah, control board, not playfield. It was late. I thought some of those Bally EMs had control boards that could lift out like that.

Ugh. Someone else's project. Definitely order up that schematic.

#18 6 years ago

DMD

songofsixpence

Quoted from MarkG:
Ugh. Someone else's project. Definitely order up that schematic.

Will do.

With nothing to lose, I took that silver wire bundle off that lug, and cobbled together a hack, connecting the white wire on one side, and the yellow on the other. now, it sorta-kinda works a bit more. At least the motor starts, although it doesn't complete a reset sequence.

Anyway, I'm through tinkering with it until the schematic arrives.

#19 6 years ago

DMD

songofsixpence