Your model number seems to be missing several digits at the end of it.

A lot depends on how long you have to unplug it to get it working again re: did it actually do a manual defrost of the evaporator coils. This would take quite a while.
Although it sounds like a sealing problem it could be a defrost problem.
A symptom of a defrost problem is that the evaporator/freezer coils ice/frost up to the point that the fan can no longer pull air through them.

Check that the unit is level side to side.
Check that the unit is level front to back or leaning slightly to the back.
Check that both doors hang correctly.
Check the door hinges for slop or a broken insert etc.
Check that the door seals and the frame are clean.

For a door seal problem get a 2 inch wide piece of paper place it between the door seal and the unit's frame. Then pull it out to see how good the deal is.
Work your way around both doors.

Check the hinge side of the seal. Sometimes they can grab the frame and twist causing a poor seal. If this is the case a light coating of lithium grease or vaseline should solve this.