My DWC283BLS wine cooler is not cooling anymore, the compressor is running constantly but the temperature inside stays between 68 and 72. Fans are working, I took the inside back panel off to make sure coils were clean and notice ice forming around the thin copper tubes above the evaporator coils (which are completely clean and without moisture or ice buildup). I cleaned up the ice and let it dry up for probably half a day... after I checked that it was completely dry, I put the inside back panel back on and put everything else back in its place and plugin the wine cooler again. I let it run overnight and this morning I saw it didn't cool below 69... so I took it apart again and there was some ice formed up again on the thin copper tubes above that are above the evaporator coils. Could someone tell me what is the probable cause and what can I do about it.
Thank you.

Furniture - Danby - DWC283BLS Wine Cooler