Some questions

[dmitri]

But I checked everything with a multimeter if there are good connections, and if there are any short circuits.

Wiring is also correct. Three MUXs are working properly, and thier signals are sending to the PC.

But the cause of the problem with the sleeve, I can't find.

Ok, suppose I am wrong and everything is solder good, cabling is good, PCB is good, resistors and capacitors are good, MUXers are good, Atmega and PIC are good. What is it left than what might be causing the problem?

If all jacks are connected to ground, it's probably not such a thing should happen.

I didn't get this.

[krzak]

What is it left than what might be causing the problem?

I don't know what might be causing the problem.

I'm not saying you're wrong. But if MD is communicating with PC, and will be detected, I think PIC is good, the LCD shows and executes software uploaded to the Atmega, I believe that Atmega is good, the PC receives signals from the MUXs, I think they are good. LCD shows correct active input, I think the Cabling is good.

[dmitri]

What is it left than what might be causing the problem?

I don't know what might be causing the problem.

I'm not saying you're wrong. But if MD is communicating with PC, and will be detected, I think PIC is good, the LCD shows and executes software uploaded to the Atmega, I believe that Atmega is good, the PC receives signals from the MUXs, I think they are good. LCD shows correct active input, I think the Cabling is good.

Than, you may have any of these left:
1. PCBs are not good
2. soldering is not good
3. leftover flux
4. some resistor/capacitors have wrong values or broken.

[krzak]

I made two films, which shows my problem. In the first, i am not sure what happens. I don't know whether it is a ground problem, but it shows what happens when i touch piezo by hand. Second shows what happens when i touch any jacks sleeve. In the movie i touch only one or two sleeves. It shows what happens with Hihat pedal row, and this, that MD stop sending signal to PC.

I can't upload this to online player.

Link: http://sendfile.pl/80745/f.rar

[dmitri]

Sorry, but I don't see what the problem is in either of two videos.

[krzak]

Hi

After quite long break I came back to my MD project, but i don't want to make new topic. I had problem with sending signal to PC (after touching MD inputs was stopping sending signals to PC) but fortunately this porblem gone at least on other computer.

But what i observed:

I have voltage on each input (I think it isn't normal but I am not sure).

When i searched short/breaks by multimeter I noticed that on powered MD i have connection between pads connector pin 1 and pin 40, and analog board connector between pin 15 and 16, but if I touch this pins conversely (e.g COM sonde instead of signal sonde) I don't have this connection.

If I connect a few piezo LCD shows that piezo themselves generate low signals as long as they are connected.

Does anyone have any idea what's wrong?

Best regards.

[ChrisHelvey]

Just for the record, I had this issue as well and it is an improper grounding problem on the PC. Here's how I found out:
Megadrum was working great from a Mac laptop, plugged in to power.
I happened to move my laptop to a different place and plugged it in without the ground tap, just to charge.
Then I had these same symptoms - drove me crazy.
Researched. Saw this post and thought about ground.
Unplugged the laptop to run on battery - problem gone.
Plugged into grounded outlet - problem still gone.

Without a proper ground, there is probably a signal floating via USB connector.

Make sure you have a properly grounded computer.....