Eject hole solenoid stays activated

(Topic ID: 180577)

Eject hole solenoid stays activated

By Ridgeman58

1 year ago

Topic Stats

  • 12 posts
  • 4 Pinsiders participating
  • Latest reply 1 year ago by Ridgeman58
  • No one calls this topic a favorite


Linked Games

#1 1 year ago

Hi All,
I'm pretty new to this forum and I am hoping yop can help with a problem.

I was playing my Lazer Ball when the power in my home suddenly went out and then back on, all in about a half a second.
Since that happened the solenoid for the Eject Hole (next to the drop down targets on the upper left) stays activated. By the time I realized this and found the key to access the playfield, the solenoid started smoking.
I replaced the burned out solenoid and a couple of transistors on the driver board that were bad, and checked all the fuses, but that didn't fix the problem. Any suggestions on where I should look? I don't want to go down the wrong road, so any input is welcomed.

Thanks in advance,

#2 1 year ago

varistor blown maybe?

#3 1 year ago

Does the rest of the game still work?

#4 1 year ago

I will check the varistor, as soon as I locate it.

Yes, the rest of the game still works as before.


#5 1 year ago
Quoted from PinsideTroll:

varistor blown maybe?

Wouldn't a blown varistor cause all the solenoids to lock on?

#6 1 year ago

Did you replace the correct transistors for that solenoid as shown in the schematic for your game? If you replaced the driver and pre-diver transistors for the solenoid and it still locks on during start up, you need to look 'upstream' and test the buffer chip that controls the transistors (going by memory here). That could be checked by a logic probe. If you decide to just replace it without testing, it is a relatively cheap chip. But the damage may go even further upstream to the PIA chip, so again a logic probe would help. Circuit board soldering skills will most probably be needed.

I assume you checked for short circuits to wiring when looking over the solenoid and the boards.

This kind of repair has been covered many many times here, just search on "locked on solenoid" or similar to get the background. Pinwiki does not have anything yet on solenoids for Williams System 3-7, so Clay's guide would help (costs money).

Varistor is a two leg little lolipop shaped component in the silver power box in the cabinet where the service outlet is. It is probably not your problem unless the whole game is now dead.

Good luck, let us know how it goes and what the final answer was.

Don C.

#7 1 year ago

Thanks Don.
Great info here. I don't have a logic tester, so I may opt to just replace the components in that circuit. I have experience in PCB soldering and de-soldering, so that is not a problem. I will install sockets for the chips while I'm at it. I will keep you posted.


#8 1 year ago

For $30, a logic probe is a great tool. Easy to use and it's like being able to see inside the chips and circuits!

Don C.

#9 1 year ago

I used my DMM to test the chips, transistors and resistors. Everything seems to be in spec. I am going to order a logic probe. Any recommendations? Also, Where can I get Clay's guide you mentioned?

Thanks again for sticking with me on this.


#10 1 year ago

My logic probe is an old one I used to use a a former job- but if you search Pinside, there will undoubtedly be some recommendations. I just looked in Amazon and saw basic ones in the $30 range. Some have batteries, some are powered off the board via alligator clips. Looks like Pinsider TerryB has done a nice write up: https://pinside.com/pinball/forum/topic/terrybs-guide-to-logic-probes

Clay Harrell produced a set of repair guides that are very useful. Some, like the one you need, are not free, he would like a donation. Contact Clay thru his site: http://pinrepair.com/

Sounds like you have done a good job on the diagnosis so far, eliminating the transistors. Next most likely thing to go is the buffer or the PIA or both. Other passive components like resistors or diodes could be part of the problem, but that is less likely.

Get the logic probe, see what's up with your chips and then see if you need to buy the guide. If you look carefully at the schematics you should be able to determine which chips the signals pass through. If there is only one solenoid acting up, it's likely that it is one section in the chip related to one leg on the buffer chip (first one upstream from the pre-driver transistor.

So do some reading on Pinside and get up to speed on the theory of solenoid control, and order up a probe, you should be able to make some progress.

Don C.

#11 1 year ago

Thanks Don.
I have already isolated the circuit on the Driver board. I will definitely check out your links with a new logic probe.
Unfortunately, work is rearing its ugly head so I have to put this on the back burner. I will keep you posted.

I really appreciate your input.


1 week later
#12 1 year ago

So I received my logic probe, reinstalled the driver board in the head, reconnected the switch that actuates the Elect Hole solenoid and turned on the machine. With the Eject Hole solenoid not connected, I noticed a second solenoid that locks on. It is the drop target reset solenoid ("BA" or "LL"). I still have to get under the playfield to confirm which one. But, I'm thinking, with 2 Solenoids locked on it should make it easier to isolate the suspect IC on the schematic.

I'll let you know what I find


Promoted items from the Pinside Marketplace
$ 104.00
From: $ 9.00
$ 20.00
Various Other Swag
Project Pinball Charity
$ 6.00
$ 22.00
Yorktown Parts and Equip
$ 4,800.00
Pinball Machine
Pappy's Pinball Palace
$ 14.00
$ 9.99
Matt's Basement Arcade
$ 999.00
Pinball Machine
$ 99.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 59.99
$ 43.00
Playfield - Toys/Add-ons
$ 69.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 5.00
Playfield - Other
Chrome Candy
$ 229.99
Lighting - Other
Lighted Pinball Mods
$ 6,995.00
Pinball Machine
Little Shop Of Games
$ 69.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 4.00
Professor Pinball
$ 49.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
$ 7.95
Apparel - Unisex
Pinball Wheezer
€ 8.10
Flipper Parts

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside