I have a 48" side by side Viking refrigerator, about 20 years old. refilled the freon last year, refilled it 3 months ago, and now I am getting the low temp alert again. Technician came by and said I am losing pressure due to a leak somewhere...most likely within the walls. Not-repairable, fridge is garbage.

before I go out trying to replace it, wanted to know what the options are. Any tests that can be done to check where the leak is (like a smoke test that can show me if the leak is external or internal)...can i cut the frdige walls to replace the hose and then repair/seal the wall? .....or is the fridge truly garbage?