Replaced defrost timer and defrost thermostat in Kenmore top freezer refrigerator. Defrost heater tests OK. Both compressor fan and fan in freezer are working. Was getting ice on coils in freezer but seems to be doing better. But... only ice will freeze solid, meats and other items won't freeze. Temp in fridge section seems OK.. also cleaned coils under fridge. Not sure what else to do. Any help would be greatly appreciated.

defrost heater tests OK

How did you test defrost heater? How many elements does heater have. Probably has two and only one is working.
Replace heating elements. If timer and thermostat are working the only thing left to be defective is heating element. Last one I replace only had one element was working. Replacement came with thermostat and both elements. Literature with new heater advised that both should be replaced because if one had failed the other one would fail shortly.

If there is no ice build up on evaporator coils then look at air flow over coils and then refrigerant charge.

The only thing I can think of is the air flow from freezer coils to refrigerator section has to be too high. Close down the air valve and open door to refrigerator a few times to start compressor and see what happens. The t-stat in refrigerator section turns on compressor and the only way to make the freezer colder is to change the air flow. You want the compressor to run longer to have to cool refrigerator section. Try this and let us know how it does, and get a thermometer so you will know the temp, two would be better. It should be at least zero in freezer. DrTom4444

Fridge has a fixed airflow from freezer. Can't adjust airflow unless I block one of two vents from freezer. Bottom portion of coils in freezer now have a light coat of frost on them. Should there be any frost at all? Or does it frost up between defrost cylces? Tested heating element with digital fluke meter. Found values I should see online. What should it read on ohm meter if good/bad? Tested old timer and thermo before and both were bad. Installed new timer and thermo. This freezer only has one heating element at bottom of coils.

The entire coil should have a light coating of frost between defrost cycles. If the unit ran for very long with frosted over coils and a bad defrost system I would suspect bad valves in the compressor. Feeling of the compressor while it is running will help diagnose it. If it is very hot and the condenser coils are not very warm then you need a new compressor. The compressor is not pumping all that it should. It has a five-year warranty on it. When a compressor is not pumping enough the compressor gets very, very hot. It should run cool or just warm and have a frost line to the edge of the cabinet. DrTom4444

OK. So checked compressor and coils and coils have almost no warmth to them. Feel room temp. when you touch top of compressor, after about 5-10 seconds, temp starts to become painful. I guess that's my problem. Bad compressor. Thanks

That is exactly right. It's not moving any heat out of the freezer. If it was the coils would be warm and the compressor cool. May not be worth replacing it. DrTom4444