Question about WPC aux 8 driver board

[brad808]

I recently got a sttng that had no drop target up coil. I just got my coil in tonight, put it in and got nothing. Replace q14 tip102 on the aux 8 driver board and replaced 2n4403 predriver at q6 on the aux 8 but still get nothing. If I ground out the metal tab on the tip 102 the coil fires as it should. Is the most likely culprit the 74ALS576 latch now? Is there anything else I should be looking at first before I order one? Any way to test that chip?

Thanks for any help.

 

[flyer666]

what happens in the test settings ????

 

[Menace]

Check to see if any of the other Aux-8 devices are working as well, and if not I'd start looking at the ribbon cables.

D

 

[brad808]

All other aux 8 devices are working fine. In test mode nothing happens. I can scroll through the other coils on the board and they fire normally.

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[brad808]

The problem is definitely on the board, I just swapped another one in and everything is working.

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[Menace]

Ok, then I would check and re-check all of the traces on the board from the header pins all the way back to the logic chip with a DMM on "buzz". If all of the traces check out, then I'd suspect a bad 576.

D

 

[brad808]

OK I got it sorted, there was a bad trace at r23. That's the good news. The bad news is that when I swapped in my alternate board, which I thought was working 100%, the cannon switches couldn't find home. I'll leave that board for a little while because I have the original working now but I'll have to add that to the list of things to fix :-\. Thanks for the guidance it's appreciated.

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