• It finally happened, I've accidentally plugged in the lipo connector backwards on the breakout. At first I thought the whole board died, but it looked like the regulator failed before reaching the chip itself, and so powering the breakout via the 3.3v pins still work.

    For now I need to design in an external 3.3v regulator for my projects, but I was just wondering if I can replace the regulator myself? I looked at the pdf schematics but I can't seem to find where the regulator is, and I have no experience with eagle files.

    I've also tried searching the forum to find out what kind of regulator it is and I couldn't seem to find any info on that.

  • I think I found something here: http://forum.espruino.com/comments/14796­787/ the MCP1703T

    Now I just need to find out where it is :D

  • Found the datasheet as well https://my.mouser.com/datasheet/2/268/22­049a-51817.pdf and I'm guessing the package on the breakout is 3-Pin SOT-23A

    Nice to know about this regulator, didn't know about it before :)

  • Wow, sorry to hear that - usually those JST connectors have a key in them? Glad nothing else was damaged though!

    But yes, it's the 3.3v SOT23 MCP1703T - I believe MCP1703T-3302E-CB

    It should be reasonably easy to get hold of - here's a mouser link: https://www.mouser.co.uk/ProductDetail/M­icrochip-Technology/MCP1703T-3302E-CB

    But depending where you are you might have a bunch of postage :)

  • They did, but I was powering off the breakout via the other vin pins as that would suit the design better (off to the side rather than at the top so it's lower profile) and I ran out of the female connector, which then set off the accident :D

    Thanks for the link, I might be able to get a bunch via digikey or the local element14 :) If they really do break first on reverse polarity, that could be a cheap extra way to protect the more important and expensive portions of the circuit! :)

  • Just an update: it works! :)

    My order for the voltage regulators from digikey just came and although I knew that they were small, I didn't expect it to be really small when not soldered to anything.

    It wasn't my best soldering job as my hands are too shaky with the tight tolerances around the components, but even though I bodged it the module works again :)

    1 Attachment

    • IMG_20200730_210454.jpg
  • Great! Glad to hear it's all ok again!

    Yes, those things are a bit fiddly, especially if you're not using a hot air gun :)

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Is it possible to replace the voltage regulator for the MDBT42Q breakout?

Posted by Avatar for parasquid @parasquid