U3 burned a hole in itself?

  • I've been setting up my DuetWifi, deux5, and paneldue 7i. First, the duet couldn't see the Deux5 (tried M115) then the paneldue stopped working. I took a look at my controller and something was glowing. Turns out, whatever IC is at U3 burned out. Looks like a Buck converter but I can't tell anymore. Anyone have any ideas of how this happened, or if it's worth fixing?

    A couple pics here:


  • short 12v to 5v is a decent guess... hotend and fan perhaps.

  • Hotend fan was plugged into deux5 on one of the fan headers since it needed 12V. But that's a good theory. I'll check things that could have been plugged in to 12v/24v and 5v at the same time.

  • administrators

    Yes, U3 is the 5V buck regulator. I've never seen one burn out before. However, if D2 has failed either open circuit or short circuit then I guess it would probably take U3 with it.

    Looks like you have a version 1.04 board, so it should still be under warranty.

  • Thanks for the information. I looked for D2 but I couldn't find it, there's a lot of stuff going on around that regulator. Is it worth me tracking it down or should I go for warranty?

    If D2 caused the buck failure, would it damage the deux5 or paneldue? Also if U3 failed for a different reason, would it damage the deux5 or paneldue? I'm hoping only the main board is damaged.

    The board was purchased maybe a month ago, by someone who is moving tomorrow. This might complicate the warranty stuff if I go that route.

  • I found D2, and it has failed short, I think. I haven't removed it from the board though, so it could be shorted elsewhere.

Log in to reply