My Emerson CR280 will turn on, get things somewhat cold then shut down and "may not" come back on. It ran for days after I first bought it....staying at about 45 degrees. Then it just decided to "not" get up to temp, shutting off shortly after I turn the knob back to "Off" then on and setting it about halfway up the dial. It's like brand new, so no dust and other problems are evident. Plenty of air circulating and it's directly plugged into the wall outlet. The wall outlet is fine too.