Audio output does not work

#1

Hello,

I own the axoloti core for a year or so and haven't had the time to use it much. But the last days I finally finished my enclosure and connected potentiometer and switches to the board. I built an expander board using perf board and used pin head connectors to connect it to the axoloti. Today I uploaded my finished patch and wanted to try it out with my other gear and I realized that the 1/4" audio output does not work. There is a little bit of signal, but it is extremely low, even with the gain on my mixer cranked up. On the other hand is the headphone output working fine. No problems here. So I tried it with other cables, other patches and had a look at almost every setting, but nothing helped. There is/was definitely no short or something. After soldering the parts to the board, I checked everything with a multimeter to see if there are shorts or other issues before powering it up. Does anyone have an idea what the problem could be? Thanks in advance...

#2

The 1/4” output is stereo, are you using a correct TRS cable?

#3

Hello, yes I tried all kind of mono and stereo cables. I connected my oscilloscope to the output testpoints, there is no signal at all. Nothing. So I really fear that the board is somehow broken. I checked the schematics and they are a bit confussing (because of the net labels), but it looks like that the signal from the headphone output and audio output is both coming out of this one audio codec ic. I never came across of a partly broken ic, most of the times they just broken or fully working. So I really hope that there is just a software problem. I tried the rescue flash thing, but that didn't help either.

#4

Did this Axoloti ever work correctly?

#5

Jap it worked. Worked also for some hours in the enclosure. It stopped working after I connected it to the pc to upload a new patch.

#6

Have you tried other patches from the library?

#7

Yes, I tried at least 10 different patches, but I will try again on monday. But I really don't think, that it will work then. Hmm I am pretty confussed. I have to try a more systematic approach to localize the failure soon.

#8

I finally found some time to have another look at the board. It seems that IC4 is somehow broken. I don't know how this could happen, but probably I fried it through a electrostatic discharge?! I did find another thread about a similar problem here: https://sebiik.github.io/community.axoloti.com.backup/t/might-have-fried-the-output-of-axo/573/28

So I guess that I need to buy some smd soldering gear now... :confounded: