Cleared Code 888/Cube turns on but no noise - not functioning

Hi! I had an 888 code. I followed the instructions and cleared the code. The unit turns on as far as the display board showing the temperature and I can adjust the temp up and down but the rest of the unit is not working (no fan noise, doesn't seem to be circulating water and the temp never adjusts automatically as if it is cooling or heating. I'm trying to determine if there are more steps to attempt or if I need to replace a part. I also don't know which part(s) I'd start with. FYI, the 888 code appeared after our friends at Centerpoint had a brief "lights out" flash and despite me having the unit plugged into a power surge device for just such occasions. Please note I am not at ALL mechanically inclined and while I enjoy learning new things, please keep in mind I'm a 63 year old woman without a lot of fixit experience, so please response as if you are speaking to a - 63 year old woman without a lot of fixit experience. Thank you for any assistance you can provide. Autumn