Hey all — I’m having a weird issue with an Alchitry Au V2 and wanted to see if anyone has run into something similar or can provide assistance.
I received the board two days ago from Sparkfun. Initially plugging it into USB, it had the default LED sweep animation. I was able to program it once using Alchitry Labs with my own simple LED-walk “Hello World” binary, which worked just fine. Between that and my next programming attempt, the board suddenly lost power and was unable to communicate with the computer. No soldering or hardware modifications were done, and it was only ever plugged into a computer USB-C port. It had probably only been powered and in use for around 10 minutes total before the failure.
It was working normally, then suddenly stopped powering from its own USB-C port. I tried multiple cables and USB ports and now get no LEDs at all. I also have an Alchitry FT+ V2 connected, and when powering through the FT+ I am able to partially power the Au V2, but it is not functional.
A few measurements/details:
-
About 40 mV across the Au V2
+/-power points when powered from its own USB -
About 360 ohms between
+and-with the board unplugged -
If I connect an FT+ V2 and power through that, I get about 4.7 V on the Au’s
+/-points -
In that state the Au lights a few LEDs in a weird pattern and gets noticeably hot
-
With both USB connections present, Alchitry Loader still detects the Au V2 and lets me program it, but the simple LED-walking bitstream that was previously working just flashes all the LEDs once and stops
I purchased the Au V2 through SparkFun and have already opened a support request with them, as well as emailed Alchitry support. I also found the previous forum thread about the UVLO issue on some earlier Au V2 boards, so I’m wondering whether this could be related or whether this sounds more like a regulator/power-rail failure.
Has anyone seen this behavior before? I’d also appreciate any advice from Alchitry on whether there are any useful measurements I can make to diagnose it, or whether I should just proceed with an RMA through sparkfun or alchitry.
Thanks!
Daniel