Fridge not defrosting

[Segilla]

The inside rear panel in my 3 year-old fridge, normally gently dripping water into the tray, is now iced up, about 1cm thick. The door seals appear to be good. What's going on?

[Panic Button]

I have no idea if it will work, but I would try the computer trick of turning it for a while and turning it on again.

[andrea81]

Might sound too simple, and sorry if you already thought of it, but is it up too high, they should be on about 3 (most are).

You never know, someone might have turned it up!

Sorry if I�m stating obvious!

[mibn2cweus]

I've experienced a situation where it appeared that the fan in the freezer compartment must of been temporarily jammed (no pun intended).

The fans operation was evidently crucial to the defrosting process.

To correct the problem required a thorough defrosting of the defrosting assembly. Even the drain hose was filled with ice.

Restoring the operating capability of the defrost assembly provided problem free operation of all functions in the years that followed to this day.

[Clanad]

I addition to mibn's diagnosis, it sounds suspiciously like a failed defrost element. Inside the panel you've described is at least one light bulb looking affair (about an inch in diameter and perhaps 4 to 5 inches in length) that provides heat during the deforst cycle to melt the ice. These fail about every 3 to 4 years. I'm describing what I've experienced here in the U.S. and assuming some similarity.
If, after melting and drying the area (be sure to unplug the fridge), the panel is fairly easy to remove with just a few screws. Don't damage the gasket that's around at least the bottom of the panel. Afterward, you'll see the heater(s). They're not expensive, so, if there's more than one, I'd replace both. You'll see that they plug into a receptacle.
Now's a good time to flush some warm, clear water with a little detergent through the inlet to the drain mibn described. It's also a good time to thoroughly clean the tray underneath. It'll have a lot of gunk in it.
Replace the panel, plug it in and run it through a defrost cycle. During the cycle, you'll hear the fan previously described. It circulates the warm air to assist in melting the ice.
In normal operation, only a little ice and frost builds up, melts, drains and starts all over again from a timer or sensor...
Best of luck!

[Segilla]

Many thanks to all for your helpful suggestions.