20W AC 220V עד 12V LED ספק כוח התקן שנאי אלקטרוני

I ordered 3 pieces. 2 of them are defective. 1x see photos, full short circuit when switching on, board burst. 2. Board does not bring any output voltage.

I will not assemble this part for now. 220V power input with 2 red wires and 12V output with 2 white wires. What is plus and what is minus?

The product was good, the delivery was bad, the delivery man did not want to go up to the floor of the delivery address, he called twice on the phone, hesitating to go up.

I say when i connect them if they are good or no SO i jUST tRYED oNE aND iT rEALY WoRED gOOD