Dawoo American style fridge/freezer sudenly stopped freezing/cooling?

As you have not provided a model number we cannot give accurate advice. But, as a general rule, with many American style fridge freezers, the first place to check would be the circulation fan that may be located behind the interior back panel of the freezer side. Can't say if this is relevant to your particular model, but I've come across this problem with other brands. Repair was a case of taking out freezer shelves and drawers and unscrewing and prising out a plastic panel in the rear of the freezer to expose a motorised fan that had failed and needed replacing. See if you can expose the fan/s and power up to see if you can see the fan turning and aslo hear the compressor kicking in.. (You may need to hold down door light switch to trick the system into thinking doors are closed before it will start up)
Other possible faults could be down to failed temperature sensors or circuit board issues.

Rupert
January 2020