Strange bug with flashing red led and low voltage report

[mtyas]

Hi
On one of my boards, I'm having a strange bug. When I plug it in, after a short initialisation, the red led flashes (at around 120bpm) and the green one stays on.
The console manages to connect to it but it says my 5v : 0.11V and VDD : 0.08V
I've removed the SD card, tried with 9V external power supply and even un-soldered the VDD pins I had (leaving all the others). In every case, it does the same.
I tried booting it up with S2 pressed (same result) and even tried to do a rescue flash.
I measured the voltage coming from the VDD and VDDA, and they are around 3.14V (so it seems good) VDDC is at 0.75V
Voltages from the gpio's seem good too.
When I try to run a patch, it seems to start (I managed to light up a led on digital GPIO), but then seems to freeze (can get it to flash, and nothing shows on the disp/scope objects)

I don't know what I've done wrong, my two other boards work fine with the same setup (USB cable, computer...)

Any ideas ?

[johannes]

Is that a revision 1.0 board?
Looks like the issue documented here:

Axoloti Core Board Failures

A few unexpected board failures have been reported, here's the analysis. Scope Affects board revision 1.0, fixed in board revision 1.1 Symptoms: The red LED keeps blinking forever after startup, while green LED is steady on Establishing connection is still possible, but extremely low voltages are reported for the 5V supply and the VDD supply, and patches don't run. IC3 (right behind the output jack) becomes extremely hot (all three!) Failure analysis: While any short on the audio powe…

[mtyas]

Thanks Johannes, didn't see that thread, it is a 1.0 board, so I'll try and get myself some diodes for my boards (all 3 are 1.0).
After reading the thread, does it mean that this particular board is now damaged and I need to get a new one ?

[johannes]

Yes, it is damaged, there is a workaround documented here:

Might have fried the output of Axo

Hello! I was going to try a new patch and in a rush of enthusiasm I forgot to disconnect the Axo from the USB power connector. There was a buzzing sound as i plugged in a TRS into the input and I might have touched the GPIO pins closest to the three glued caps in the corner. Now there's only a weak digital noise on one channel and a very weak output on the other one. The emulator shows signals both on the input and output correctly. : / However, the headphone output works as it should thank g…

[mtyas]

Just a quick update to say that by following your advice I've managed to fix it.
Thanks a lot @johannes for the great customer service. I really didn't think I was going to manage to mend it, with my big lumberjack fingers and by below average soldering skills. But it seems to work well again. Here are a few photos to give you a heart attack (if ever you needed one)
Thanks again

Uploading...

P.S I've covered the bottom side fix up with hot glue to avoid any unwanted contact since I took the photos, because everything is close to each other. And it still works

[philoop]

On one of my boards, I'm having a strange bug. When I plug it in, after a short initialisation, the red led flashes (at around 120bpm) and the green one stays on.
The console manages to connect to it but it says my 5v : 0.11V and VDD : 0.08V

after loading a patch to internal flash as startup, this happend, but ic 3 doesnt get warm ...
what to do?

[mtyas]

Can't you get it to work anymore at all ?
I can't remember the ic3 getting warm, but it was all blocked otherwise, so I coudn't do anything else than try this to mend it, which it did.
Ask @johannes maybe, he's the best source of information hardware wise (if he hasn't already contacted you by pm)

[AdrianWillaert]

I have something similar but not so serious:
my red led is always steady, axoloti works good but Voltage indicator on Axoloti app keeps fluctuating between 4.87 and 5.04 while on my other axoloti is steady and no red light.
Is the same issue?