My freezer has two sets of cooling coils. The top one is working but the bottom one, which cools the bottom two shelves is not freezing. Any suggestions as to what the problem could be and any solutions? Thanks

door gasket is leaking

Obviously that freezer is not achieved the required temperature. There are several reasons for that:
- Defrosting system is not working, which leads to accumulation too much ice on the evaporator that prevents heat transfer and reduces air circulation despite the fan is running.
- The problem with draining condensate after defrosting cycle which also leads to accumulation of ice.
- Leaking gas from the cooling system (reduced cooling capacity)
- Faulty compressor

Dado

your cooling matchine get damaged,there having a cooling matchine.

Open freezer door and look for any frost on the back wall inside the freezer. That would indicate a defrost problem.
Disconnect power to refrig. Unload freezer, Remove shelves and back panel inside freezer. Melt frost with a hair blower. Replace defrost heater located at the bottom of the heating coils. (Note: It may look different than the original, but insturctions enclosed with replacement cover that) Might as well replace the evaporator thermister at the same time, as your problem is about 98% of the time one or the other of those parts. The thermister is a white pencil shapped item, about an inch long, located cliped to the top of the cooling coils you just defrosted.
If you don't have the parts on hand, defrosting only will get your refrig working again for several days, while you obtain the parts.
Note: non-water dispensing is the result of the cold air from the freezer not being able to continue over the frost blocked coils, so it migrates back though the return air vent in the bottom of the refrig, resulting in a frozen water line, and often freezing in the bottom bin of the refrig.

Unplug refrig. Empty all food from freezer side and remove shelves from freezer. Remove back metal cover from inside freezer. Melt frost with a hair blower. Examine defrost heater at very bottom of the coils you defrosted. If heater coil inside glass tube is broken, replace defrost heater. (note: replacement may look different, but insturctions included with replacement address that) If heater is not broken, replace the small white pencil shapped sensor at the top of the cooling coils.

Sounds like you have a frost blocked evaporator. That the term for a refrigerator which is not automatically defrosting. Unload the freezer, remove the shelves and the back wall out of the freezer, melt the frost with a hair dryer, replace the defrost heater at the bottom of the cooling coils and replace the white 1.5 inch long sensor at the top of the cooling coils.

Unload freezer, remove shelves, take panel out at back of freezer and use a hair dryer to melt all the built up frost and ice off the cooling coils. Replace the defrost heater, located at the bottom of the cooling coils. (it may appear different looking than the original, so follow instructions which come witht the new defrost heater)

you have clogged drain

I just had a similar problem, and the bottoms of both sides were cold but the top shelves were warm. I found that the condenser fan, the fan right above the cooling coils was not working. This fan circulates the cold air and if it's not working it can't move the cold air to the top or over to the refrigerator side. Open the freezer door and press the switch that tells the computer the door is closed (so the light goes out), if the fan doesn't come on shortly, or only sputters that could be the problem. You will need to take out the back cover over the coils, the ice maker tray and auger motor if you have one and some other parts. Play around with the plug where it goes into the side wall, if you can get the fan to come on and off, it's most likely a bad fan motor....about $55 to replace. As you take it apart, be sure to take some digital pics of the process so you can remember how it goes back together!

good then go ahead and ohm out the sensor and the relays to see if the resistance is close to the normat. 70 degrees is roughly 1000 ohms. relay you are lookling for continuity or open. then you can also ohm the fan motor too. let me know what you find;.that will determin whts bad and whats good