LCD screen light flashes without power

[RadekPilich]

I have posted an explainer here, if you want to go deeper, ask Gemini

Digitone LEDs flashing when Power off

This is supposedly caused by the “polarity” of the ungrounded power supplies. Simply try turning the plug in the socket 180 degrees and see if it gets resolved. More precise approach would be to go through the whole chain of power distribution before and making sure that the phase and neutral contacts don’t get flipped between the conditioners, switches, extension cords or whatever you got there. Depending on where you live, even grounded devices with non-symmetrical plugs might be wired inco…