[akspencefamily]

Noticed that the food inside was thawing, especially close to the bottom. Emptied unit, defrosted, then plugged it back in. Frost only forms on 15% of the top shelf. Other shelfs, which have had frost build-up in the past, are frost-free. Wondering what the problem is & what is the next step - thanks.

[denman]

Sounds like you have a freon leak and are now low on freon.
Also may be a compressor problem.
I am assuming that the compressor runs all the time trying to lower the temperature in the unit.

Since it is a sealed system problem you will need a pro to fix it and it will be expensive. Often it makes more sense to put those dollars towards a new unit.