After a week passed without word from ARB, I called and left a message with a tech support person. Soon thereafter I received an email from ARB stating that it would promptly ship a replacement fridge, with a return label for the defective one. No hassle at all! (Good that I'd sent a video/audio with my claim.) That is great customer service ... two months before the three-year warranty expired.
I will add that while waiting to hear back from ARB, I did contact SnoMaster (which uses its own compressors, not Secop/Danfoss compressors.) The fellow said they, too, get a few similar warranty claims each year. So, it happens.