I’ve an 18 month old Samsung american style side by side fridge freezer, RS21 NGRS twin cooling version. The freezer temp is OK but the Fridge is high. When I looked inside at the bottom it was frosted up. If you turn it off you get an error code on the fridge side indicator… the right hand 8 bottom led is lit, then goes off. I can’t hear a fan working. I read some of the other topics on the forum which indicate a number of possibles… the fan being one of them.. Is the fan the sole issue, or do I typically need to test any other components ?