Big Bang Piggy Bankin DOT FAIL with new power supply

[Jiisus]

Hello all,

     Once again having issues with the 40x Dotmation i posted about years ago. It's basically the same issue as before; after the first startup bong, one reel spin, and the PROM1/PROM2 startup screen, it will display the Williams logo on the display for a few seconds, make a quick "err" buzz sound, display turns off and displays "DOT FAIL" on the 7 segment displays. Diagnostic LEDs inside the cabinet seem to be correct (single LED on the left off, five on the right all on). Fiddling with the soft clear button inside the cabinet can sometimes bring it to life for a couple of minutes before it shuts off again.

     Last time this happened, it was the DOT control board that ended up being the issue. Bought one from a user here and it worked again for a couple of years. Assuming it was the same thing, we bought another one and it hasn't fixed the issue. I then replaced the upper power supply with a switching supply using the tutorial linked here. Still no change. I've checked all the cables running from the control board/power supply to the display and they don't have any breaks.

     I am running out of ideas. I assume the next place would be the lower power supply? that's about the only thing I can think of. Anyone have any other ideas?

Thank you,

Ryan

[dragster73]

You said:   I've checked all the cables running from the control board/power supply to the display and they don't have any breaks.

These normally fail where they are crimped and you can not visually see it. You would have to have a ribbon cable tester to know if it is good or not.

You could try flipping the cable on both ends so that the red stripe is in the opposite direction to see if anything changes.

Basically the Game board is not properly communicating with the CPU. Perhaps the problem is on the CPU. You could try reseating the boards in the cage by removing them and pushing them back in.

[Jiisus]

Thanks for the response.

I checked the ribbon cable using component legs and a continuity meter - every pin showed good. Would it fail outside of that? Flipping the ribbon cable did not change anything.

Reseating the CPU boards made it work one time, after a longer boot up sequence (I assume because the boards were removed). Cutting the power off and back on, it had the same error again.

Is there a procedure for testing the CPU? I do not have another machine to test with.

Thank you

[Chris-socal]

You just hit the nail on the head. Best option would be to install the board in a known working cabinet and see if it behaves the same. If you can officially rule out game board you know you are dealing with something else.

Have you by any chance clipped onto the board and monitored the voltage? Just be sure you are clipping onto a regular component and not a high voltage DMD driver that can be upwards of 60-120v. It wouldn’t be the end of the world, its not 14,000 v or anything. Actually it might be interesting to monitor the hv feed to see if it is dropping.


Chris

[Jiisus]

Chris,

     I do not have another cabinet that I can test with. Where are you referring to that I should be testing for voltage?

Thanks,
Ryan

[Chris-socal]

Sorry about that. I sometimes forget that not everyone is familiar with circuit hoards and such.
Each of the ICs on the driver board probably run on 5v DC. I was suggesting you take a mini grabber and clip onto the 5v and and leads and just see if the 5v rail on that board is stable. If the 5v rail isn’t holding steady and above 4.9 volts the board might be crashing.
I don’t really know anything specific about DMD circuits specifically I just know power supplies are often the cause of random shut downs.not always, but often.

You could send the board to another member who has the same machine or contact one of our supporting businesses like Midwest Slots or K-Lar. Their contact information is on the home page.

Chris

[playklax01]

There's also the comm cable from the backplane to the dotmation controller.  From what you stated, the slot itself seems to be booting fine and the dotmation system seems to be initializing fine.  If the communication between the game proper and the dotmation system is broken it would cause a Dot Fail like you're getting.  There are 2 connection ports on the dotmation controller, you could try the other connector to see if that makes a difference.  If that doesn't work, reseating the cable on the backplane (kind of hard to get to) would be next.