The first signs of a failing refrigerator are warm shelves, unusual noises, frost buildup, water under the unit

https://telegra.ph/Why-Samsung-and-Whirlpool-refrigerator-issues-show-up-more-often-01-04

The first signs of a failing refrigerator are warm shelves, unusual noises, frost buildup, water under the unit, or food spoiling faster than usual.