Amana bottom freezer/fridge top model.
Freezer works fine - cold as it should be. Air blows around freely in the freezer. However fridge on top is not cooling.
I pulled the back inside panel off the freezer and there was considerable frost (white flakes). It was peculiar though, in that there was a very distinct line of frost on the coils/fins. Below the line was heavily frosted, above the line (closest to the fan) was completely frost free.
So I'm thinking the defrost timer or defrost unit, correct? But what is this very distinct line of frost telling me? Could it indicate which part is bad?

Thanks for reply.
If you mean on the inside wall of the freezer against the coils - no, not a considerable amount of frost. Maybe ever so slightly if I scratched a fingernail against it, but not noticable.
For your second question -
The bottom half of the coils were 90-100% covered in frost - inbetween and on outside surface.
The top half of the coils were virtually free of any ice or frost.
There was a very distinct demarcation line between the top and bottom - below the line was the frost, above the line no frost.

Since I posted, I "defrosted" the coils and the refrig has returned to cooling normally. I'm watching the coils closely to see if frost continue to build up - in the day since I defrosted no frost has returned but I think it is too early to really tell. I still think based on what happened something is not functioning correctly. Thanks for any added input you may have.

Thanks Gene. I guess I'm not understanding what the compressor has to do with frost build up. Shouldn't the defrost mechnism be independent of the compressor?