(Topic ID: 182248)

White Water WPC switch matrix issue


By faustus66

2 years ago



Topic Stats

  • 6 posts
  • 3 Pinsiders participating
  • Latest reply 2 years ago by faustus66
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#1 2 years ago

Hi All,

It's been a long time since I worked on my White Water and I'm bringing it back from 10 years of just sitting there.

I am trying to diagnose a switch matrix issue. Columns 1,5,6,7,8 all work fine, but columns 2,3,4 are all dead.

I am diagnosing this with the machine on and running a single jumper from j206 to j208 so it's not a playfield side issue.

I have replaced U20 and U14 with sockets and new chips, but not a single change in behaviour.

What are the next steps in diagnosis?

Much appreciated, it would be great to play WW again.

Thanks

Adrian

#2 2 years ago

For what it's worth I have now tried a logic probe on J206 and J208 and all pins are pulsing high. I also checked the legs of U20 and one side were all pulsing high and the other side were all pulsing low.

#3 2 years ago

So hmm. Obvious question, but we are talking switches 21-28, 31-38, 41-48 here right? Because if it's 12, 22, 32, 42, 52 etc instead them it's probably rows that are bad and would point to a simple u18. I'm sure this isn't the case but just a thought.

Also is switch 24 on? Does the game boot up with check fuse f114/f115 error?

Lastly, have you tried the testing also with the ribbon cable pulled from the power driver board? Sometimes a bad u7/u8 on the power board can confuse the switch matrix.

Also to verify, you have checked continuity from u20 pin 17 to j206 pin 2, u20 pin 16 to j206 pin 3, u20 pin 15 to j206 pin 4?

#4 2 years ago

Battery acid damage to board?

#5 2 years ago

Thank you so much for the replies.

> So hmm. Obvious question, but we are talking switches 21-28, 31-38, 41-48 here right? Because if it's 12, 22, 32, 42, 52 etc instead them it's probably rows that are bad and would point to a simple u18. I'm sure this isn't the case but just a thought.

it is 21-28, 31-38, 41-48

> Also is switch 24 on? Does the game boot up with check fuse f114/f115 error?

Switch 24 is not on but I have not seen the f114/115 message. Will check next time I put the board back in.

> Lastly, have you tried the testing also with the ribbon cable pulled from the power driver board? Sometimes a bad u7/u8 on the power board can confuse the switch matrix.

When I put the board back in I will test this too.

> Also to verify, you have checked continuity from u20 pin 17 to j206 pin 2, u20 pin 16 to j206 pin 3, u20 pin 15 to j206 pin 4?

I think you have found it, the continuity tests fail for the pins on the chip to the j206 pins. I will trace these tracks and see what is failing..

Thanks heaps.

Adrian

1 week later
#6 2 years ago

This is now solved, there was indeed a break in continuity between J206 and u20. Thanks

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