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BBAI (possibly) dead

edited January 2021 in BeagleBone AI

I (had) a BBAI running as a KiwiRX - and it has been happily running in 8 channel mode for a few months - until a few days ago. I noticed that it had crashed (no lights, no response) and power-cycled it, and it came right up again.

A day later, I noticed that it had locked up again and another power cycle brought it back up - for an hour or so - and now there is no visible activity at all, with or without the KiwiSDR board plugged in.

Having verified the power supply - and tried a different power supply - before I spin my wheels and shotgun everything, is there something that I should be checking? My next step was going to be an attempt to boot on a virgin image on the microSD.

Clint

Comments

  • Has it been well cooled?

    Things stopping after an hour or so are normally thermal or bad disk in my experience.

    Assuming you've not been thrashing the on board storage I'd look at cooling.

    If the cpu/board has been heat cycling strongly the solder might have crystallized and when hot there is enough expansion to disconnect a pin or two. To check I'd let it cool (to the point it started when you last got an hour run) then boot it with less cooling see if it fails sooner, they should throttle back but I be careful just reduce the cooling not risk running without.

    If it is disk I think there are images for the BBAI to run from SD, disconnect the cape and test that for while.

    Stu

    njc
  • The BBAI in question has spent most of its life (about 7 months) running at 1 GHz with a cooling fan, so it hasn't had much opportunity to thermally-cycle - but based on the nature of the failure, I suspect that a mechanical failure has occurred on a BGA or something.

    Based on this, I have concluded that it is probably dead: There are no lights, ever - even with a new micro-SD image, and having let it sit for a few days un-caped. Although all of the correct voltages appear to be present on the available test points, only the PMIC seems to be dissipating any power at all (it is only very slightly warm).

    As far as I can tell, there's probably nothing to be done (I haven't figure out if any warranty might apply) to fix it. If anyone has any other ideas, I'd be interested.

    Oh well: Since the Kiwi board itself is (probably) fine, I've ordered a BBG to replace it. Anyway, I never found the BBAI to have much of an advantage: Never did it the Kiwi process restart on its own after an update (it always required a power cycle - something others have also reported) and the hassle of trying to use it with 14 receive channels (e.g. extra cooling, etc.) wasn't really worth the trouble.


    73,

    Clint, KA7OEI

  • edited February 2021

    Have you tried a display on it in case there is any clues there? Or using the boot + reset buttons?

    I do wish BegleBone had gone somewhere between the Standard and AI, 14CH doesn't need a massive increase in CPU and the other cores are not useful in this application so the resulting heat can't help in a radio receiver (RF Thermal noise). That is part of my reason for spending so much time with drills, files and passive heatsink enclosures.

    I hope your AI is not dead just pretending to be a brick.

    73 Stu

    --edit-- Assuming BGA failure you could support the bottom of the PCB and apply light pressure to the CPU heatsink then try to boot.

    NVIDIA GPU's in some older laptops failed due to solder and flexing the PCB through pressure on the keyboard (before they disconnected enough to crash it) would change the visual faults.

  • I do think that the use of the Kiwi cape on a Pi is a great (if unofficially unsupported) way to get the 14 channels with less thermal issues and more actual processing power - and at a significantly lower price. I do own a BBAI and it's currently unused because I haven't yet had the time to sort a half-decent cooling solution for it.

    I completely respect and stand by John's decision to not support KiwiSDR on the RaspberrySDR devices - even though I own one myself, currently used as the source for my multiband FT8 decoding.

    I am likely to migrate one of my genuine Kiwis over to a Pi from the BBG, and have that device for all of my WSPR decoding and management. The primary Kiwi at that point will be exclusively for the public's use. I might also change out the RasperrySDR to be my personal plaything for listening and DRM decoding etc, it'll never be publicly accessible anyway, and its FT8 sensitivity isn't as good as I would actually like to have.

    I have a QTH move to Zurich to concentrate on over the next month, and my playing radio will take a back seat to getting accommodation etc sorted.

    @ka7oei If everything else you have tried has failed to breath life into the BBAI you have, it may be worth trying to reflow the BGA and other possible bad connections by carefully baking in an oven. I have no specific advice on this, but there is apparently plenty on the web to help.

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