Normally articles like these have a pithy intro, but before anything else, check to see if the water line is leaking.
Step 1: Check if the leak is from the water line!
If your fridge has a water dispenser or ice marker, there is a plastic tube in the back that brings in water. Slowly wheel your fridge forward to take a peek behind it. If you see water coming out of the tubing, you need to either stem the tide with some plumbers tape or turn off the water.
This is the first thing to check because, at least in the short term, not addressing a leak in the line will only turn your kitchen into a tidal zone.
To catch a water issues early, think about getting a smart dampness detector. These small devices can keep an eye out for you in hard-to-see places so you can catch small problems before they become major incidences.
Step 2: Check to see if the light comes on
If there isn't a major leak, you need to think methodically. The next disaster comes if there an issue with the power supply, because in a day or two all your food will spoil.
With no electricity, water will start to flow out as your frozen foods and ice start to melt, as well as condensation building up inside your fridge.
A quick peek inside the fridge to see if the light comes on is an easy way to check if the unit is getting power. Your fridge may also have a control panel with exterior lights.
Lets say the light doesn't come on, you should wait a bit and listen to hear if your fridge makes any noise, i.e drawing power. You don't want to open the fridge for an extended period of time because that would cause the food to spoil faster, if it is broken.
A fridge that's not drawing power means a call to a service provider, and possibly a purchase of a new fridge.
Step 3: Inspect your food containers
At this junction, a lot of guides will point you towards the defrost drain. However, when I troubleshoot, I go through emergencies first, then all the possibilities from least time consuming to check to most.
It's pretty easy to do a spot check of all your food containers to make sure they aren't cracked. You should pay special attention to any that have recently spent time in the microwave. I'd also keep an eye out for anything in the rear of the fridge that's tipped over. There aren't enough numbers in the universe to count how many times a youngster has crammed a juice carton back into the fridge, knocking something over in the back.
Step 4: Check the drain and drip pan
Did you know your fridge has a drain and a drip pan? The drain is usually found at the bottom of the fridge and freezer compartments. The pan is found at the very bottom of the fridge, where you can't see.
They usually come into play during a defrost cycle. The water that builds up inside your fridge flows through the drains and collect into the pan to be evaporated. Ever wonder why your fridge is making a dripping noise? Defrost waste collecting in the drip pan is the reason.
Your fridge's manual should have information on how to maintain these systems. Usually it involves a bit of scraping or some warm water to get the water flow evenly again. Be sure to remember to unplug the fridge while your working.