An arguably better replacement for the resistor in a CRC power supply - R21 PS module

[tombo56]

Red LED flashing, if input voltage is lower than set output, is not a primary function, just a neat side effect. With output set to 17.5 V, some load and input dropped to 17 V, red LED should start to slowly flash or “wink at you” or at least be lit continuously.

Green LED indicates power on.

 

[ItsAllInMyHead]

That coincides perfectly with what I see. Thanks!