LM2596S - Config process has no effect

Wondering if anyone has experience with this DC-DC module?
The instructions say to hold the button >4 seconds after power on to configure/adjust the input and output voltages (I need to output 5v from a 12v input). However nothing happens doing that. The display just switches off and I cannot enter any information.
Has anyone else had this problem?
Best Regards,



  • Hello,
    May I kindly ask did you connect the power supply input?

  • Hello,
    Yes, power supply input was there. Red light came on and input voltage displayed. Able to switch to output voltage (same as input - 1v). But no ability to enter config mode to tune the input or output.
    Best Regards,

  • Any more on this?

  • SunSun
    edited July 5

    Hello D, I also tried the product page method and it really doesn't work. That method is used to calibrate the output voltage value though, it doesn't correct your output voltage. You need to adjust the resistor value by rotating the copper coloured notch on the adjustable resistor. The change in resistance value will change the voltage output. Hopes this help you.

    Please also check to see if your mailbox is not receiving mail properly. Have a good weekend.

  • Hello Sun,
    Yes, I understood that you are supposed to be able to change the output by tuning the pot, however nothing was being changed by altering that, turning in any direction, as my multimeter confirmed.
    I believe this unit was defective when I received it, as now the device is simply showing the red light, with no display of the input voltage, and will not change to the green light or show the output voltage, or anything, on the display.
    Very disappointing.

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