When the slow cooker unit was plugged in and set to low it began to buzz and displayed and err message for a few seconds and then went into a series of "8" being displayed. The buzzing is very loud. This is my second issue with this unit. I had a cracked pot and was one month out of warranty when I purchased a new one. I have used slow cookers for years and know how to use them properly. It would appear the microprocessor is bad? Is the unit non-repairable?