Arduino Pro Micro 5V (VCC pin outputs only 4.4V) (Solved)

Is there anyone who knows what could be the reason of it? I tested it with 2 different instances and it always gives only 4.3V -4.5V despite fact that the datasheet clearly says VCC pin should output 5V…

Btw I tried an experiment, instead of using micro USB I supplied the power from Arduino Uno’s 5V pin by connecting it to the “Raw” pin of Pro Micro and VCC gave 4.8V.

The project requires to have no additional power of source, I’d like to use USB connection only. Is there anyone who knows what alternative solution I could use? The problem is that too low voltage disrupts the work of a module connected to the Pro Micro…

  • Maybe it's you PC, what is the voltage on your PC USB cable?
  • Could be your micro's USB MOS FET switch is bad.

just had a quick play around - if you bridge the two J1 solder pads up near the micro USB connector you should by pass the voltage reg and VCC will pretty much match USB in (Im getting 5.05V at VCC with the J1 pads shorted) so long as your USB 5V is stable and stays under 5.2V then should be OK

worked well :slight_smile: If anyone has a problem with some module that works on "Uno" but doesn't work on "Pro Micro Leonardo" due to low voltage then this could be helpful;p

Btw I never recommend anything like that but this guy is a really good seller

I have the same one as yours. After searching mentioned that its voltage supply is upto 12V and I connected it to 12V power supply. Now it's not running any more. I intend to remove a small IC chip that I think it's a regulator. But it's really small and very difficult to remove. But i don't want to waste my time if the chip was damaged. What should I do now?

SOT-23-6/5 is easy to remove. Just blob a lot of solder on top and use a wide tip, so you heat all pins at once. Comes off real easy.

But - determine what the problem is before you start swapping parts...