(Topic ID: 297884)

Roadshow DMD problems

By Jawbreaker

4 months ago



Topic Stats

  • 2 posts
  • 2 Pinsiders participating
  • Latest reply 4 months ago by Crash
  • Topic is favorited by 1 Pinsider

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#1 4 months ago

I need help troubleshooting this problem I’m having with my Roadshow. Yesterday I decided to replace the batteries in all of my games with lithium AA’s. No problem. I’m not sure if it’s related but when I came home later that day I noticed the DMD on my RS was acting weird and giving me a partial image only in the top right corner. I figured when I pulled the speaker panel out to replace the batteries the data cable must’ve come loose.

I reseated the cables (power and data) on the DMD and the Dot Matrix Control Board all with no success. Today I started digging a little deeper…I started with reading the voltage to the pins on the DMD, they all seemed low so I read the j604 pins on the DMCB which read the same. I checked both fuses on the DMCB and they were fine. Then I read the incoming voltage to the board on j605 from the transformer. All of the voltages were around half of what they should be. J605-1,2 call for 80vac and read about 40vac. J605-3,5 call for 100vac and read about 50vac. I then figured out which wires coming directly off the transformer fed this cable and they were also the same half voltage.

At this point it seems like the transformer isn’t putting out the correct voltage but I’ve never had a transformer go bad in any of my games. It also seems like such a coincidence since I haven’t even turned RS on for weeks and suddenly I have display problems after a simple battery swap.

Any suggestions? Thanks in advance. BTW - I have FH, MM and WH20 also that I could swap parts from to test.

Update…after thinking more about it I realized that I was checking each in to ground forgetting I was measuring AC. After reading between 605-1 and 605-2 I do get 80vac as well as 100vac between 605-3 and 605-5, so I think the transformer is good. Here are the voltages I get at j604 pins…
1 -110vdc should be -125vdc
2 -85vdc should be -113vdc
3 key
4 ground
5 ground
6 4.85vdc should be 5vdc
7 not voltage wire
8 5.4vdc should be 62vdc

Obviously there is a problem with the output of this board. Thanks again.

-Tim

#2 4 months ago

It could be the DMD as well. Can you swap the DMD to rule it out?

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