Looking for manual and replacement shelves for the Kenmore Model 38121 Upright Freezer?

SOURCE: Whirlpool Freezer Model #EV150NXENOO

This one sounds like the defrost timer is not working and you are not getting a defrost cycle every 6-8 hours (or when needed). Another issue could be that air (moisture) is getting in from a leaky door seal, etc. and causing the freeze up. If you have a sealed system problem where the cooling coils are not uniformly frosted up then the defrost thermostat will not "know" there is an ice condition and therefore not go into defrost mode (same issue if the defrost t-stat is bad). After you have ALL the ice out of the unit it would be a good idea to take the interior rear cover off so you can view the coils. Start the freezer back up and watch over the next 1/2 hour or so to see that the entire coil is frosting up uniformly. If it isn't you may have a plugged system, a leak causing low refrigerant, etc. If over time the coils look uniformly frosted up you may have a defective defrost heating element itself (no heat, no defrost sort of thing). The defrost elements can be checked with a multimeter for continuity if you know how to do that sort of thing. It's hard to know a person's ability by these forums or if they can tackle certain test procedures.

SOURCE: Roper--ice buildup on one freezer shelf

The reason for ice buildup is an air leak. Recheck all around the gasket by taking a dollar bill and closing the door on it and pulling it out. If you don't have resistance, you found your leak. Heat that area with a blow dryer to relax the gasket and close the door to let the magnet and seal set. Also, rub some vasoline on the hinge side gasket to keep it from dragging.

SOURCE: maytag upright freezer model MQU1556AEW

I experienced the same problem last week with my freezer. Apparently the change in temperature during defrosting allows the blade locking mechanism to slide on the motor shaft during the spinning operation. The blade pulls itself along the shaft until it comes in contact with the motor mounting bolt. If your freezer just stops getting super cold, but remains cool and you don't hear the fan spinning, remove the inside back panel and check the fan blades for freedom of movement. I almost disposed of the freezer this past week but decided to make one last check of the mechanisms.

SOURCE: Kenmore upright freezer alarm sounds constantly

replace the battery in the grill or the hi-voltage control under the unit in the back

SOURCE: Sears Ken Elite upright freezer model no 25329082991 temp alarm

alarm should go off when freezer reaches minus 18c or lower.