I'm currently following the tutorial "Electronics Fun Kit" by ELEGOO. The goal is to connect the power supply module with the breadboard in order to provide a 3.3V / 5 V source.

After connecting the power supply module and powering it with a 12V adapt, the LED of the module is on.

Therefore I'm assuming that I've powered it correctly.

Now when setting the jumper of the power supply module to 3.3V, I am able to measure this voltage (3.30V) on the breadboard, by using my multimeter (set to 20V DC.) So far so good.

But when setting the jumper of the power supply module to 5V, I somehow measure 11.47V. How is this possible? Is it a typical "beginner" mistake or is the hardware not ok?

PS: I know that the probes are not correctly connected to the multimeter. I've already changed that, but I still have the same measurement results

Voltage on breadboard with 3.3V Jumper on power supply module

Voltage on breadboard with 5V Jumper on power supply module

  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – Voltage Spike
    Jun 8, 2020 at 22:33

1 Answer 1


My guess is that you have fried the supply circuit when you first measured the voltage using the current input of your multimeter.

This will most likely have shorted the supply out, letting the input voltage be applied directly to the 5V output.

  • \$\begingroup\$ They weren’t using the current input as such, since the black lead was in the voltage measurement terminal instead of Com. Since the 3.3V reads correctly, it seems unlikely that this is shorting the output. \$\endgroup\$
    – Arkku
    Apr 16, 2020 at 12:30
  • 1
    \$\begingroup\$ But why is only the 5V affected? \$\endgroup\$
    – babbadeckl
    Apr 16, 2020 at 12:40
  • 2
    \$\begingroup\$ If it was a short his voltage reading would have been 0. \$\endgroup\$ Apr 16, 2020 at 12:42
  • \$\begingroup\$ @babbadeckl there are two different regulators on the board. The 5v one seems fried. Not saying he fried it, but its gone either way. \$\endgroup\$ Apr 17, 2020 at 12:23

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