Frost free refrigerator issues....
We normally check the defrost heater and defrost thermostat first, if one of these check as being bad we change them out first.
LINK> Defrost heater kit
How to a defrost heater, this is the same procedure for a glass tube heater or an calrod style heater...
Defrost thermostat.
LINK> Defrost thermostat
Refrigerator Defrost Thermostat Testing.
If the defrost heater and defrost thermostat check out ok, then we change out the defrost control ( could be a timer or electronic board ).
LINK> Defrost timer kit, 8 hour, replaces most/instructions included, Manufacturer Number 482493
LINK> Electronic control, Jazz board, Manufacturer Number W10503278
LINK> Do-it-yourself repair manual- Refrigerator, Manufacturer Number 787808L
jeff.