Second build has shipped. Message will appear here when store is ready for third build ordering.

KiwiSDR V2 keeps powering down [BBG manufacturing defect]

My new V2 keeps powering down for no apparent reason.

I have to disconnect and reconnect from PSU to restart.

Any ideas?


  • What type of power supply do you use, can you measure the voltages on the kiwi board, particularly 5V/5VE?

    In another thread you mentioned that you were using a relay board, does it happen when you switch it?

  • edited March 9

    No, not using a relay board with the V2.

    I don't beleive you can't access the 5V/5VE pins without full disassembly of the V2.

    The PSUs (there are two one for each of the V1 and the V2) are professionally custom built linear 3.5 amp with toroidal transformer. The professional who built them is me.

    The PSU was the one that has been powering the V1 for the last year with out issue. I then swapped them over and the issue stayed with the V2.

    I can't see anything in the log, is there a way to see previous logs and not just the current session?

    Edit, I am taking the V2 apart to see what I find.

  • It may be that V1 was just on the edge of an acceptable PSU start up / close down voltage vs. time, and the V2 isn't.

    It is a problem with linear supplies, as they ramp up and ramp down much slower than switched mode designs, when connected and disconnected from the mains. Plugging and unplugging the DC cable from the KiWi is pretty much instantaneous, which is probably why that seems to work OK.

    The KiWi's have always been slightly touchy about this.



  • edited March 9

    You can see older logs if you log in with ssh and type "journalctl |tail -n 1000"

    (1000 is the last number of lines that you want to see, it will take a few seconds)

  • Okay issue corrected. There was a high resistance through board solder connection on the Beaglebone board on one of the 5v rails. I don't foresee any further issues now it has been corrected, unless Beaglebones are prone to bad assembly issues. Are they?

    BTW, there are no issues with my linear PSUs , I use nothing else in the shack for RX use, certainly not SWM.

  • jksjks
    edited March 9

    Can you tell me exactly what/where the Beagle fault was? With a photo possibly? Email to if you don't want to post here.

    I'd like to understand the issue so I can have our assembly/test guy look for it.

    We've had a few of Beagles we've purchased recently have SD card slot problems. But that's all.

    Thank you.

  • I have reassembled it all now.

    When I dismantle it to connect the Antenna switch I will take a photo then. But there really won't be anything to see as it wasn't visible to the naked eye, only to my bench test equipment.

    There was a through board connection that carries 5 volt, the solder flow was obviously not perfect as there was a voltage drop across that through connection. I have been dealing with this type of intermittent issue for 50 years now in my business, so I know what I'm looking for.

  • Was it where the header pins are soldered to the board? That's not surprising I guess as I believe they have to use selective soldering equipment separate from the SMT reflow oven process to handle the TH header.

    Thanks for the info.

  • No it was away from the header pins. I told you, it was a through board connection, which would've been flow soldered. These sort of connections are prone to bad joints on any multi layered PCBs. Having the BBG in the V1 for comparison readings made the troubleshooting a lot quicker.

Sign In or Register to comment.