Sudden malfunction of certain channels

[derbstens]

Hello,
i have an abrubt malfunction of auxilary channel 4 and 5.
I cannot isolate the problem yet but let me describe the symptoms:

Out of nowhere I have channel aux 4 emittin constant false triggering on note 27 which is mapped to
China 2 in superior Drummer2.
The channel is hooked to a selfmade brass cymbal with a 30mm Piezo, it was working fine for two years now.
When looking at the cannel via Megadrum Manager, I can make changes but only gradually change the levels of the false triggerings.
The constant note on/off persists when detaching the cable from the channel.
Updating/reinstallment of Firmware did not help.
I changed the hardware input to aux 5 and the problem accured again at a certain point in our set.
We do patch changes whith a computer hooked to our digital preamps, which also worked fine for years.
The DAW Software has no software connecting to the Megadrum Module.
I will get my facts straight later today for detailed version info and routing.
Has anyone hat this sort of malfunction?
Best,

Derbstens

[dmitri]

If it's not a hardware problem (cable or piezo) then I would guess that you set either Threshold too low or Gain too high.

[derbstens]

That is most likely not the case.
As mentioned, the channel worked fine and went out of control whithout the possibility to reset it.
Setting threshold as high as 60 stops the constant note triggering, but also cuts any signal that comes from the cymbal.
Besides that it worked at a threshold level of 20 or so, the false trigger persists when detaching cable from the unit itself, when resetting the channel and also when reinstalling Firmware.
Can a channel become corrupt by a piezo?
Is it possible that the MDM receives a sysex command somehow?

Also the right encoder racts peculiar:
When trying to store a setup to stot 1 when pushing right encoder to confirm, the LCD jumpst to end of menu...

[dmitri]

That is most likely not the case.
As mentioned, the channel worked fine and went out of control whithout the possibility to reset it.
Setting threshold as high as 60 stops the constant note triggering, but also cuts any signal that comes from the cymbal.
Besides that it worked at a threshold level of 20 or so, the false trigger persists when detaching cable from the unit itself, when resetting the channel and also when reinstalling Firmware.
Can a channel become corrupt by a piezo?

Never heard of these and very unlikely.

Is it possible that the MDM receives a sysex command somehow?

Not sure I understand the question.

Also the right encoder racts peculiar:
When trying to store a setup to stot 1 when pushing right encoder to confirm, the LCD jumpst to end of menu...

Looks like the buttons cable is connected in reverse. Have you opened the module and did something inside?

Also, if you boot MegaDrum with default settings, i.e. with AutoLoadConf set to No, are Aux4 and Aux5 still triggering without anything connected to them?

[derbstens]

I'll be happy to provide you whith detailed and confirmed information, when I come to the rehearsal room tonight.
I actually opened the unit to see if some connection has gone loose, I'll check on that first.
Then I can load default settings.
Thanks for your suggestions so far.
If there is any other Info you need to be provided whith, let me know.

[derbstens]

Corrected wrong encoder wiring, set unit to 'autoload conf: no',
Restarted unit, channel Aux 5 H still triggers continuously.
Disabeled Aux 5,
Enabeled Aux 4, the channel i had the symptom on, the first time.
Aux 4 seems to be in the same faulty state, contiuously emmits whatever note it is set to.
Restarted unit whithout daw, atoload conf no, still cannel Aux 4 and 5 are faluty.
Firmware version: 2140318
MCU STM 32 F 103 R CT 6.

I will update to most recent verson next.

[derbstens]

Done.
Aux 4 and 5 do the same false triggering as before update.

[derbstens]

So after having disconnected the inputs from the pcb, the false triggering persists.
I fear it could have to do with our DAW Reaper. It's sending patch changes to our digital preamps via RME Fireface and although it is not connected to an input channel of the MD on any midi track, both times the continuous false triggering started in a certain song.
We get the drums via MD hooked to USB and connected to SD2 (Superior Drummer) then fed to inear mixer.

I have no idea what to try next. It seems most likely, that it is a hardware problem, which is pretty bad as my band is rehearsing inear only

[dmitri]

If both Aux4 and Aux5 are still triggering with default settings and nothing connected to the module then I'm afraid it is indeed a hardware problem on the main board for this two inputs. If you have spare inputs I can suggest to disable these two Aux inputs and use two others. If you used up all inputs I can only suggest to check all soldering points around the MUXer connected to these two inputs and may be trying to "hot touch" with a soldering iron those points.

[dmitri]

I guess you built your module using an old Atmega644 based MegaDrum kit, so check and "hot touch" all solder points inside the red circle shown in this picture:

pcb_back_soldering_points.jpg