(Topic ID: 146775)

Williams System 11C - Coils Fire with Flashers

By pinheadpurdy

4 years ago

Topic Stats

  • 11 posts
  • 5 Pinsiders participating
  • Latest reply 4 years ago by GRUMPY
  • Topic is favorited by 2 Pinsiders


Linked Games

#1 4 years ago

I have a problem with my System 11C Rollergames. When three of the ramp flashers fire, each one of them triggers a separate coil at the same time. Flasher #5 fires VUK, Flasher #6 fires Drop Targets, and Flasher #7 fires Cabinet Knocker. The coils work separately when they're supposed to and do not fire the associated flashers. It behaves the same in diagnostics mode (video to come). I have 8 month old brand new main power board, aux power board and interconnect board. When I disconnect the flashers from the interconnect board, the problem still happens so I don't think it's a short. There have been a couple components replaced on the MPU board in the lower left corner (where I believe these signals originate). The same problem cropped up months ago, but I can't remember what I did to fix it and the game has worked great for the last six months. Any thoughts? Thanks!

#2 4 years ago

Have you looked at the A/C relay?

#3 4 years ago

The relay on the MPU or the one on the Aux Power Board? I put my old Aux Power Board back in and it did the exact same thing, so I doubt it's that relay unless they're both bad. I'm not sure about the one on the MPU. Is there a good was to test these? Thanks!

#4 4 years ago

The A/C select relay is located on the aux power driver board.

It's possible that the transistor that controls it is shorted.

When you run solenoid test, I believe there's a test selection for A/C relay. If you run the test, do you hear the relay click on and off as solenoid test cycles?

#5 4 years ago

That'd be the relay on the Auxillary Power Driver board, I believe.

To test, I traced the leads going to the internal contacts to the relay. It's a make/break relay, so just verify the continuity. I'm not sure if you can manually actuate it though.

#6 4 years ago

The relay on both Aux boards 'click' and sound normal. There is a diag LED in the interconnect board that comes on when the relay engages and it looks normal too, although that LED does stay on sometimes. Does that sound normal?

So if the Aux Power Driver Board is the problem that means I have two bad aux pwr boards - the original and the newish Kohout. I did have trouble with the first Kohout Aux board I got 8 mo ago, but when I put the old one back in the problem went away. This is not happening now - both new and old behave the same way.

I believe I can manually actuate it in the test mode by just waiting for a full cycle. I'm not real swift with the DMM though.

#7 4 years ago

there one under the playing field as well.

#9 4 years ago

Do you want to fix this yourself or are you going to send the board out for repair?

1 week later
#10 4 years ago

Update; I pulled the aux pwr driver board out of the other RG that I am buying and the problem went away! I guess I do have two A/C relays that failed in the same way.

Does anyone have insight into why they fail? Is the machine backfeeding something into the aux driver board causing the A/C relay to fail? Thanks for all the help guys. Grumpy - there is a local operator that fixes boards.

#11 4 years ago

I'm not sure it's the A/C relay that went bad, I'm leaning toward some diodes. You will have to do more testing if you need to know for sure.

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