(Topic ID: 221690)

Eight Ball Bally - 1A Playfield Fuse blowing - Slingshots & Middle Pop

By crazi

3 years ago


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  • 20 posts
  • 8 Pinsiders participating
  • Latest reply 57 days ago by pins4u
  • Topic is favorited by 1 Pinsider

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#1 3 years ago

Hi All - so i'm reviving a dead 8 ball. Have fixed the MPU so it now goes in to attract mode. Got the displays up and running. No Sound but I will get there.

1A playfield fuse was blown. Put in a new one and ran the solenoid test and it popped the 1A fuse again. So I decided to sacrifice a few fuses. Ran an earth to each Tip on the Driver board to activate each solenoid one at a time. All worked fine except for BOTH slingshots and middle (lower) Pop Bumper blow the 1A fuse. It would fire the coil but then pop the fuse.

So must be a short?

Checked the diode on each of the 3 coils - all ok. Checked the coils out of circuit with the diodes off. Slingshots 7 Ohms and Pop 3.7 Ohms (all 3 seem ok to me)

No wires on the switches are touching anything they shouldn't.

So what next?

Ta in advance

#2 3 years ago

Were you using a slow blow?

#3 3 years ago

Yes an SB.

#4 3 years ago
Quoted from crazi:

Checked the coils out of circuit with the diodes off. Slingshots 7 Ohms and Pop 3.7 Ohms (all 3 seem ok to me)

Slingshot and pop bumper coils are the same spec and should measure around 11 ohms. Compare against one of the working pop bumper coils.
Some of the Marco coil wrappers list the DC resistance - see 10.7Ω here:
https://www.marcospecialties.com//images/products/AE1-26-1200/additional1/large.jpg

#5 3 years ago

Are you sure it's supposed to only be 1A?

Usually, coils have 2 to 3A fuses. Did you read the amperage off a label on the playfield or the schematics?

#6 3 years ago
Quoted from ForceFlow:

Are you sure it's supposed to only be 1A?

1A slow blow fuse under the playfield for the solenoids is pretty standard for Ballys of that era.

#7 3 years ago

Working coils are measuring between 10 and 11 ohm.

Would a 3 Ohm (7 Ohm difference) be enough to pop the fuse?

Like wise the Slings are measuring 7.1 Ohm would a 3 Ohm difference pop the fuse?

#8 3 years ago

Pinched wire somewhere?

Correct coils installed?

Have you taken the suspect coils completely off the machine and examined the coils all around the wrapper for a coil winding that may have become abraded or grounded to the frame?

#9 3 years ago
Quoted from crazi:

Would a 3 Ohm (7 Ohm difference) be enough to pop the fuse?

Yes, that's nearly 3 times the current being drawn.

Quoted from crazi:

Working coils are measuring between 10 and 11 ohm....
Like wise the Slings are measuring 7.1 Ohm would a 3 Ohm difference pop the fuse?

The fact that the coils at proper spec of 11 ohms aren't blowing the fuse and the 7.1 ohm coils are should answer that question

Are they all 26-1200 coils or has someone installed the wrong ones? Do they look like they're cooked?
BTW when you checked the diodes on those coils, did you you test the diodes disconnected?

#10 3 years ago
Quoted from crazi:

Would a 3 Ohm (7 Ohm difference) be enough to pop the fuse?

Like wise the Slings are measuring 7.1 Ohm would a 3 Ohm difference pop the fuse?

They might or might not in general, but when you're testing by manually grounding who knows how long of a pulse you really gave?

#11 3 years ago

Yes tested the diodes disconnected.

The Pop coil doesnt look great. It's a 26-1200

The slings look ok but the original wrappers are gone so not sure what they are. They should be 25-950 (that's what working on my other 8 Ball)

When grounding it was a quick touch but it's the same result during game diagnostics tests as well. Pops the 1A

QUESTION

I have 2x 23-840 coils and 1x 23-800 in stock - can I use them?? Widely used on Williams

#12 3 years ago

You linked Eight Ball Deluxe to your thread, but only mention 8 Ball in text. Which game is it?
Nevertheless, both manuals state the Pop Bumpers and Slingshots are AN-26-1200 coils:
.
8Ball_Coils.jpg
EBD_Coils.jpg

#13 3 years ago
Quoted from crazi:

I have 2x 23-840 coils and 1x 23-800 in stock - can I use them?? Widely used on Williams

Not compatible. Williams used 25V, Bally uses 50V.

#14 3 years ago

Cheers thanks for the coil info

So as 1A is quite low for coils. I tried a 2.5A and reconnected the slings. They are working fine. Is 2.5A fuse ok???

Going to reconnect the pop and see if it blows the fuse. If so I will order a coil.

#15 3 years ago
Quoted from crazi:

So as 1A is quite low for coils.

I think Bally would disagree with that.. As zacaj mentioned you're comparing to different manufacturer/voltage games.

#16 3 years ago
Quoted from crazi:

Cheers thanks for the coil info
So as 1A is quite low for coils. I tried a 2.5A and reconnected the slings. They are working fine. Is 2.5A fuse ok???
Going to reconnect the pop and see if it blows the fuse. If so I will order a coil.

Order 3 coils, since they're all out of range, and leave it at 1A. If you're blowing the 1A that means that you're hurting the transistor when you put in the 2.5A

#17 3 years ago

I also would strongly advise against leaving that 2.5a fuse in there--that's how board components can melt/fry/burn a hole in the board, etc and lead you to a bigger problem than you had to start with. The guys here are right on the money, follow their advice and your game will be happy (and you will, too!)

Good luck!

#18 3 years ago

Have ordered 3 new coils. I agree.

Ive just noticed the out kicker, Saucer and 4 bank target set aren't working. Need to check the diagram but I think they get driven through the solenoid relay a/b type. Not used to Bally so it's like starting over

3 years later
#19 57 days ago

I had this happen to me today, Replaced the fuse & quickly discovered the center popbumper engaged. switched off and did a multi-meter check on the solenoid trannys. Q12 was shorted ON. so replaced the tranny, replaced the fuse and all good again. So the fuse popped but so did the tip102 tranny. That fuse saved the driverboard from even more damage. A 1 Amp slo-blo nothing higher. Pin was a Stern Wild Fyre by the way.

#20 57 days ago
Quoted from Gemini2544:

I had this happen to me today, Replaced the fuse & quickly discovered the center popbumper engaged. switched off and did a multi-meter check on the solenoid trannys. Q12 was shorted ON. so replaced the tranny, replaced the fuse and all good again. So the fuse popped but so did the tip102 tranny. That fuse saved the driverboard from even more damage. A 1 Amp slo-blo nothing higher. Pin was a Stern Wild Fyre by the way.

The transistor shorted FIRST and then the fuse popped. The popped fuse was a result of the transistor shorting.

Transistors will fail LONG before a fuse can react.

You are right, the correct fuse probably prevented damage to the board after the transistor shorted.

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