Hello AppliancePartsPro forum!

I'm investigating a malfunctioning < 3 year old Samsung refrigerator. One day, I noticed a dense layer of frost on the contents of the freezer. A day or so later, we noticed the same contents thawing and water leaking from the bottom of the fridge. Both the freezer and fridge side seemed unusually warm. Ice cream had melted completely.

We unplugged the fridge, waited a day, plugged it back in to no avail.

Investigating the compressor, it seemed to be working (it was warm, was making the usual humming noises we'd grown used to). The coils on the interior of the freezer and fridge were cold, but neither fan was working.

Testing the fans with a 9V battery connected to the red and black wires revealed the fans to be in working order: they spun up immediately and without issue.

I'm wondering if this is an issue with a sensor controlling the fans - or more worringly, the motherboard? I've included a picture of the two boards at the back of the unit, each with a conspicuous red light lit up.

Does this suggest any obvious issue or fix? I'm not sure how to troubleshoot a sensor issue, but imagine its an easier part to replace than the motherboard. What do you think is best?

Does the angle of the bend in this seem too acute? I'm wondering if this is contributing to the absence of cooling/fan functionality. Is the corrosion pointing to anything in particular?