Short circuit on 2nd multiplexer

[shdw]

Hello,
I've just built my own Mega Drum. I've started to test it yesterday in Addictive Drums and first thing I noticed was ride playing whole time. On MD LCD there is one trigger signal sending all time, even without any inputs connected. Could you tell me when I can probably find short circuit cousing the problem (I just think its coused by short circuit). Every other inputs work great, just instead of this one. I found out that problem is in second multiplexer (it's not directly problem with multiplexer, becouse I already tested another 3).

Thanks for your help,
Regards,
Kamil

[dmitri]

If it really the Ride input, then it is in fact the first MUXer, pin 2 so you should check for shorts around there. Which Vu-meter bar on the LCD shows constant triggering?

[shdw]

I just think its ride becouse it's playing in AD but you are right, ride is on first MUXer.
Top 7th from left.

[dmitri]

Then look for a short around the pin 2 of the second MUXer.

[shdw]

I checked everywhere around pin 2 of 2nd MPXer and there is no short.
I also upgraded firmware, but it didn't help. Any ideas what can I check now?

[dmitri]

Can you check what happens if you swap 1st and 2nd MUXers?

[shdw]

(it's not directly problem with multiplexer, becouse I already tested another 3).

[dmitri]

Ok.
1. Did you solder the diodes on this input correctly and are they ok?
2. What happens if you short this input to the ground provided the diodes are ok and soldered correctly?

[mackanov]

Did you just eyeball it or did you check for continuity between the input and VCC?

[shdw]

1. Did you solder the diodes on this input correctly and are they ok?

No, I didn't. I just found out that one of the diodes was soldered wrong side. Thanks!