The machine craches after one two minutes [solved]

Nippon

Hello my machine cashed after a few minutes and it makes very loud buzzing noise so I cant hear the bass drum. I don't know what it could be.

julian

-Is the buzz there all the time?
if so, could you post audio examples?
or does it only appear after a crash?

- Do you already use an SD card with the firmware presets installed?

- Regarding restarts: is the power supply plug the correct size? does the machine stay on when you jiggle the PSU plug?

Nippon

I uploaded a 30 seconds audiofile. After this time the machine don't react anymore and the LCD shows crazy things. What I notices is that every LED makes the buzz louder.

I tried the SD-Card with presets and without.

Without it works better but not stable. (Maybe I misunderstood the question)

My power supply plug fits good.

https://soundcloud.com/baumyuga/ls-30618

bassFant

You could try a different power supply (one which delivers more current).

Nippon

But my power supply has 1200mA output. And Julian wrote that we need only at least 600mA. 

I thought it is enough. 

julian

hmmm this sounds not right at all!.
And It does not sound like a PSU problem, too.

Is this noise on all 4 audio outs?

Have you allready tried a firmware update?

A hi-res photo of your soldering would be great as well if possible.

Nippon

The noise is on all four audio outs. And I tried the firmware 0.21 and 0.24. But there was no difference.
I try to upload high res pictures the next time.
I noticed an other problem, maybe there is a relation between this. When I trigger a button 9-16 nearly every (its random which) LED will flash between this steps 9-16.

julian

Your button/LED problem sounds like a short somewhere.
The buzzing sound that gets louder could be something similar, logic signals somehow getting on the audio rails or the GND plane. 'The waveform of your demo mp3 looks like it. It seems to be a single rectangle pulse. Later on in the sound it seems to be 2 pulses (2 leds lit?)

I would continue with testing without the mainboard attached.
this way the sequencer won't be running and you are not able to set steps, but all menus and buttons should work. And you won't risk damaging the mainboard if the short is on a critical position
You should still be able to switch menus and select voices, change parameters etc.
Are the rest of the buttons working as intended? for example can you select different voices that are then shown on the menu and light the corresponding LED? Can you switch modes (voice, performance, step, load/save) and doe the LEDs light up?

the sequencer buttons 9-16 are connected to U5 (74hc165) and RR6 (10k resistor network)
LED 9-16 are connected to U3 (74hc595) and RR1 (220 ohm network)

these are the places i would look first for an error. The resistor networks have the right orientation (dot in square)?

Nippon

The button/LED problem is solved. I really head a short somewhere but I don't know where exactly.

But I stil have this buzzing sound. I realized that the sound is only on the audio outs when the mainboard is attached. Is it possible that something is wrong with the mainboard. I noticed that this two elements on the picture look a bit strange.

julian

those look strange indeed. are they loose, too?
I tested all the mainboards before sending them out (audio working on all 4 outs)
so unless they got loose while shippe, they should be fine.

The jacks on the fronpanel are directly connected to the mainboard. so when no mainboard is attached, there is nothing connected to the jacks.

can you measure the voltage on C23? shoul be a stable 3.3V
is the buzzing also there while running the bootloader? as soon as you power up the device?

julian

solved via email.
It turns out the wallwart was the problem.
Changed to another power supply and the problems were gone.