Axoloti Core Rev 1.2 Board DOA (powers up kind of I guess)?

[mypetrobot]

I recently purchased a used Axoloti Core off of reverb.com. It arrived today and when I went to power it on for the first time (using the same USB cable that I use for my other board) all I get is a really dim LED 1 (red). Here are a few other things I noticed if it's helpful:

• There is a faint pop from the audio output when I connect power.
• The board is not recognized as a USB device when attached to a computer.
• Manually pushing switch 1 causes the dim LED 1 to turn off while the switch is pressed.

Is this behavior that anyone else has experienced? Are there any troubleshooting steps I should try before I tell the seller that they sold me a dud (or it was possibly damaged during shipping)?

Thanks in advance!

[weasel79]

Never had anything like that luckily but from my amateur point of view that sounds like it's proper dead.

[janvantomme]

Have you tried to boot it in Rescue Mode (DFU)

Axoloti Hardware

Connectors and controls 3.5mm (1/8") mini-jack is a headphone output. Use only for headphones (headphone jack is electrically biased at 1.65V.) 6.35mm (1/4") Stereo connector input and output, (labeled on the backside of the circuit board). 5 pole DIN connectors are MIDI in- and output (labeled on the backside of the circuit board). micro-sd-card (should be FAT formatted) micro-usb serves connection for Axoloti software, a power source, and act as a class compliant midi device. power input: 2.…

[mypetrobot]

Just tried to start in DFU mode: While the LEDs are off when the machine first powers on, when I release S1 the Axoloti just behaves like I described in my first post (dim LED1, etc). I also get the following message in the patcher when I try "Flash (Rescue)"

No devices in DFU mode detected. To bring Axoloti Core in DFU mode, remove power from Axoloti Core, and then connect the micro-USB port to your computer while holding button S1. The LEDs will stay off when in DFU mode.

[lokki]

is there any leftover solder on any of the holes, or anything else connected to the axoloti? this sounds like a short to me. can you post a hires pic of your board?

[mypetrobot]

So I was thinking about this while I was getting ready for work this morning. It occurred to me that I may need to continue to hold S1 through the entire "Flash (Rescue)" sequence even though the instructions don't explicitly say to do this. So I brought the board into work with me and gave it a whirl.

The PC at my office immediately recognized the bootloader USB device and installed the drivers. I was able to go through the whole sequence of replacing the bootloader driver with winusb and reflashing the flash with the patcher. While I haven't tried to make the Axoloti spit out any audio yet, I did create a simple patch to make the green LED flash at me to show that it was working. Everything appears to be fine, but I guess I'll have to do some additional testing at home this evening to confirm.

Thanks for the help everyone!

[mypetrobot]

So the saga continues...

During my lunch break at the office I created a patch to make sure the presumably rescued Axoloti was functioning normally. I made it make some sound, etc. and everything worked great! I packed the thing up and brought it home thinking that I could mark this problem solved. However, when I plugged the thing into my computer at home, boom, dim red LED 1, not recognized by the PC. Gah!

I tried multiple times starting it up in DFU mode on my home PC and nothing popped up in terms of Windows finding devices and the patcher/Zadig seeing any DFU devices. One thing that I noticed this time around after I gave up on the PC is LED 1 appears to faintly/semi-regularly blink when connected to a USB cable that is plugged into an adapter/powerstrip.

I don't know what to do at this point other than trying to reflash it again at work? Even if that works that doesn't solve the issue I am experiencing at home.

Here are a few environmental factors that may contribute to this problem I guess:

• Windows 10 PC at work, Windows 7 PC at home (however I have another Axoloti that functions fine using the home PC).
• Humidity/heat or something? My office air conditioning runs so cold that I'll occasionally have to run a space heater in the summer.
• The bubblewrap that this thing was shipped in (and that I packed it in to travel to work)? Maybe static or something? I don't know, is this even a thing?

Any guidance would be greatly appreciated. Thanks!

[lokki]

same cable at work and home? different usb port?

[MattilynMattroe]

My friend's axo was having a similar problem -dim red led, not being recognized in the patcher/laptop. We tried 2 laptops, multiple usb cables with no joy. But what did work was powering it with a separate supply in the dc socket. If we did that it worked fine and connected to the laptop. So it seemed to be a problem with the usb power.

Might be a separate issue, but thought I'd share in case it helped.

[mypetrobot]

same cable at work and home? different usb port?

Same USB cable at both locations. It's actually the same cable I use for my working Axoloti at home. I have some other cables I can try. When I noticed the faint/semi-regular flickering of LED 1, the Axo was powered using a different cable connected to the AC adapter/powerstrip though.

I tried 2 different USB ports on the home computer, although they were both located on the front panel. I can try one of the back panel ones this evening.

But what did work was powering it with a separate supply in the dc socket. If we did that it worked fine and connected to the laptop.

Hmm. I'd like to try this, but I don't know if I have the appropriate AC adapter laying around. Also, I'm not sure if it is actually a USB power issue as it works fine connected to the PC at my office.

---

I was successfully able to reflash the Axoloti at this office this morning again. I'm not heading back into work until Monday, so I guess I have to plan out what troubleshooting steps I attempt as I might only get "1 shot" if plugging the thing into my PC at home some how wipes the firmware. I have a start-up patch on an SD-Card, so my thought is to attempt to connect it just to a USB cable connected to an AC adapter first. If that works, then try connecting it to the PC again.

Keep throwing suggestions my way, I'm open to whatever.

[weasel79]

If you don't have the matching AC adapter around (it takes 7-15V tho!) just try a 9v block battery? I can totally imagine faulty USB power being the issue here.

[mypetrobot]

Minor update: Plugging it into a USB AC adapter at home just now worked fine. My fear is that it is somehow related to my home PC. Somehow plugging it into this PC (despite the other Axoloti working fine using the same cable/PC/etc) corrupts the firmware. The last time I plugged it into this same USB AC adapter (after plugging it into the home PC) I was met with the dim red LED.

Is there some kind of device conflict or something I can run into managing multiple Axoloti Cores with 1 computer? I'd like as much info as I can before I inevitably kill the Axo for the weekend before I can reflash it at the office again.

[MattilynMattroe]

Not much to add other than 'that's weird'.

Regarding the multiple axoloti thing - I have 3 that all work fine on the same pc, often with 3 patchers running at once connected to each one.

[lokki]

do you have a patch saved to flash at startup? i had once a situation where an axoloti could not boot anymore because of a corrupted flashpatch. the solution was to jump over the startup patch (holding down s1 or 2 at startup) and then uploading an empty patch to flash.

[mypetrobot]

For those following along at home, I plugged the Axo into the same USB port on my PC that I tried at first using the same cable I've been using all along and it's working fine. I have no idea. The only thing I did different between the two attempts at flashing this thing was not transport it in the bubblewrap that it shipped in. The mystery may never be solved.

[weasel79]

I have shit like that happen all the time. something doesn't work, you go crazy tryingg to fix it for a day or two, then you just walk back in, turn everything on and it suddenly just works. never start questioning that, just be happy.

[lokki]

as i said, did you check there is no startup patch on flash? just to be sure write an empty one to flash. as my axoloti did this is was intermittent as well, sometimes it worked, sometimes it didn't...

[mypetrobot]

Gotcha, thanks. As I purchased this Axoloti used, I have no idea if there was a start-up patch already on the flash. I uploaded a blank one just in case.

[azaxo]

There is thread about Windows 7 related issues. Maybe that could help.

Windows 7 Install ... once more :/

It looks a little bit like a problem I had although I worked under windows 10 not under windows 7.

[steveo]

Hi @mypetrobot, I'm Matt's friend he mentioned. You're issue is almost identical to mine from what you have described.

Things I've tried to troubleshoot it:
- using different USB cables, makes no difference. Still intermittent functionality
- Try on Windows 7 laptop and a Mac OSX
- DFU start up and Flash rescue. Same problem as you where it comes out of DFU mode when I release S1. Managed to successfully complete it eventually but same issues persist.
- Disconnected all hardware from GPIOs. This made no difference but I'm actually happy about that. I was worried the knobs and LEDs I'd soldered together were the source of a grounding problem. Apparently not.
- Removed from Hammond enclosure

Some potential causes that I need to keep testing:
- I may have done some crappy soldering on the GPIO header and caused a short somewhere. I have a header strip soldered to the board and connect the knobs and LEDs with jumper leads.
- My board is bolted to a piece of perspex with rubber spacers between the board and the perspex. The perspex is then velcro'd to the hammond enclosure. I'm worried there is static building up on the perspex. Probably should have used wood instead.

Update:
In the 5 minutes while I've been typing this, the board no appears to have started working normally with a nice solid green LED. I'm so confused

I'm determined to sort this out and would love to hear if you get to the bottom of it. Let me know if any of the info above is helpful or if you have any progress. I'll keep you updated from my side.

Good luck!