I am hearing a buzzing and crackling sound from the back of fridge.

adjust the thermostat setting up to around 4
with refrigerators the lower the number the colder the fridge

Bea, try this. UNPLUG the refrigerator for 12 hours and keep the fridge and freezer doors open. You might lose some food. NOW you will find some water under the fridge. clean that and now power up the fridge. Make sure you hear the motor working. Your fridge will start cooling. Keep at recommended temp.

Typically the fridge gets its cool air from the freezer via a vent. There is likely something blocking that vent like ice. Move your food to a cooler and turn off the fridge long enough for the ice to thaw (12-24 hours).
If this does not resolve the problem then dismantling of the vents for cleaning will be required.

Normal 0 MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} The fridge gets its cold air from the freezer through a vent(damper) between the freezer and fridge.The fan in the freezer blows air through it. Make sure this fan is running. You may have to hold the door switch in for it to run. There is a flap you adjust with the fridge temp. control. Make sure it's opening and closing when you adjust the fridge temp.
The problem could be the electronic control if you have one or the mechanical linkages.

the normal temperature for a refrigerator is 35-40 degrees F, so 40 at full cold setting is not correct.

If this is a side-by-side or top-freezer, make sure that the air vents between freezer and fridge are not blocked by food items or ice.

Make sure defroster operation is working normally as ice will block airflow.

Also, there is a circulating fan in most models that moves cold air from freezer to fridge. make sure that's working.

Try shutting down your unit, unplug it from the wall and wait a few minutes - plus it back in and turn on see if it solves the problem otherwise you may have a faulty board.

There is ice buildup in an area that you cannot see.

The interior wall may "bulge" a little if the ice builds up a lot.

1. You may have the cooling dial set too high (use lower numbers)
2. The blower vent into the fridge or freezer maybe blocked (move items away from vents inside)
3. Defrost the fridge. The water pan underneath the refrigerator may overflow.

If there is no "defrost" setting, unplug for an hour (don't open refrigerator or freezer during defrost)

Plug back in, food will not spoil.

Hi the problem is with a clogged drain hose that's why all the water. to unclog turn off fridge. pull away from the wall . remove back panel. clean all vents . locate drain tube, by the drain tray. clean out the drain . thanks the appliance doc

Here's what I did, I defrosted! I found out that the fridge temp is monitored and maintained by the freezer. Because we had a power outage one night, my freezer thawed while we all slept and then when power came back on, freezer re-froze but this cause an ice build up on the vent on the back wall of the freezer. Well, ice must have been in one (or more) vents, causing blocked air flow in my top half of the refrigerator. I turned the dial in the freezer to "off" which also shuts down power to the fridge half. I then unplugged the refrigerator, hauled all my food items into coolers, opened the freezer door and refrigerator doors and left them open for a little over six hours. I took advantage of this empty fridge and freezer and wiped everything down. After this time frame passed, I plugged the fridge back in, turned the freezer dial to my preferred freezer temp, and wah-lah! Within two hours I had a cold fridge and solid ice cubes in the freezer. I then put all my food items back into their appropriate compartments, and went to work. Bear in mind, a total 24-hour period is needed for the fridge to re-set itself, but still, after two hours the fridge was noticeably cold. Who knew, besides our parents' generation: DEFROST!