I made a custom ATmega32u4 board for my project. Components came from clone of Arduino Pro Micro (with bootloader and code which I uploaded) from AliExpress. I soldered everything in to my board according to my schematic but the board doesn't work. I don't have any signal from that.



  • Did you buy the atmega32u4 with bootloader? Which bootloader? How can you be sure that it has a bootloader? Even the arduino micro has a icsp header. Can you solder wires to it for a icsp header? Then you can upload a sketch with a programmer without bootloader. For example a sketch to toggle a pin or blink a led. After that you can try to use tx and rx with a extra usb-serial module to a computer. After that you can try the bootloader and try to upload a sketch.
    – Jot
    Commented Oct 5, 2018 at 18:01
  • Firstly i upload code to orginal board and everything was working. Then i soldered everything and i dont have any response from my custom board.
    – Muzykk
    Commented Oct 5, 2018 at 18:12
  • It's hard to tell from those pictures, but do you actually have any power going into VCC?
    – Majenko
    Commented Oct 5, 2018 at 19:51
  • Now I've got into whatever EDA that is you're using I can see that no, it would appear not. You actually have to provide power to the chip for it to successfully run...
    – Majenko
    Commented Oct 5, 2018 at 19:54
  • I connect this wire and everything is working nice right now. Thanks for fast help ;)
    – Muzykk
    Commented Oct 6, 2018 at 10:35

1 Answer 1


You have an error in your schematic.

You have used the net name VCC for your main power circuit. However your USB incoming power is labelled as +5V.

That means you have two separate nets - +5V with power on it, and VCC isolated from it entirely.

You need to connect those two nets together - name them both VCC or both +5V so they form a single net (easiest is to adopt VCC since you use that on other connections too).

To "fix" your current PCB you could connect a small wire from the cathode of D2 to pin 44 AVCC on the main chip which will bridge the two nets together.

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