DOUT/LED's (worked once, but no longer)

Testing/Troubleshooting
1

It’s been a long day working with the midibox.  I’ve finally got the AIN working (had some grounding issues), the DIN working (was using the wrong pins on Smash’s fancy split cable DIN/DOUT design), and the DOUT working, sort of.  Even the LCD that I was having trouble with earlier is working.  In all, I’m quite happy with the progress. 

However…

I had the DOUT/LED’s working correctly (although I still need to assign them to the correct buttons, they were firing on different button pushes, as expected), and was sitting across the room on the sofa admiring the glow of the LCD, when all of a sudden all of the LED’s all lit up simultaneously (I have 20 in total), and will not turn off until I unplug the box.  Upon reboot, the LED’s remain lit, and the DOUT function seems to be no longer working. 

Any suggestions?  Upon searching for similar problems, I discovered TK recommending stuffing some caps in the DOUT module, but I’m not exactly sure how that would work, what value and where I should place them. 

Any assistance is greatly appreciated. 

2

Disconnect everything else, work on one problem at a time. With 20 LEDs I assume you have a DINx4 connected. Remove all SRs and see what it’s doing now. None of the LEDs should be lit. Measure the voltages on the supply pins of each SR. All good?

Stuff the first one, see what happens. If all LEDs are suddenly lit - try another SR in the place. What happens now?

3

I will do exactly that.  Thank you.

4

Well, I decided to look at things and tackle the easiest possibilities first.  I snipped off the connector to the board, redid another connector, and voila, it works.  Thank you for your assistance!