It sounds like the unpleasant smell in your fridge is likely due to the forgotten chicken that spoiled during the power outage. Here's what you can do to address the issue:
Remove the spoiled food: Open the fridge and freezer and remove any spoiled or rotting food items, especially the chicken that you had forgotten about.
Clean the interior: Empty the contents of the fridge and freezer, and then thoroughly clean the interior with a mixture of equal parts water and vinegar. Pay close attention to the areas where the spoiled food might have leaked or dripped.
Clean removable parts: Remove shelves, drawers, and any other removable parts from the fridge. Wash them with warm, soapy water, and rinse thoroughly. You can also use the water and vinegar solution for this step.
Deodorize the fridge: After cleaning, place an open box of baking soda or activated charcoal in both the fridge and freezer compartments. These substances can help absorb lingering odors. Leave the boxes in the fridge for a day or two.
Ventilate the fridge: Leave the fridge and freezer doors open for a few hours to allow fresh air to circulate and help dissipate any remaining odor.
Check the condenser coils: If your fridge has accessible condenser coils (usually located at the back or bottom of the fridge), make sure they are clean and free from dust and debris. Dirty coils can lead to odors and reduced cooling efficiency.
Inspect the drain pan: Check the drain pan located at the bottom of the fridge for any accumulated liquid or debris. Clean it if needed.
Plug the fridge back in: After completing the cleaning and deodorizing process, plug the fridge back in and let it run as usual. Monitor it for any persistent odors.
In most cases, following these steps should eliminate the foul smell from your fridge. However, if the smell persists even after cleaning, or if you suspect that the spoiled chicken has leaked into the fridge's insulation, it may be best to consult a professional appliance technician for a more thorough inspection and potential repairs.