There is no problem with your dehumidifier. The indicator screen does not work with a LED light, but with pearls that have a special color dye that reacts to humidity. 

You will notice that the pearls behind the transparent window have either an orange colour, a green colour, or a color in between. When the pearls have an orange colour the device is ready to absorb moisture. It will change to green gradually as it absorbs moisture. When the pearls have a green color the device can be regenerated.