My avanti wine cooler won't cool. I have had it unplugged now for quite some time, but I would like to fix it. Since I plugged it back in, it's about 75 and making a clicking sound every few minutes.

https://manualsdump.com/en/manuals/avanti-wc1500dss/66172/12
The above has a troubleshooting matrix.

Power supply: Check if the wine fridge is receiving power from the mains supply. If it's not, there might be a major issue with the mains power or the PSU circuit board in the product that'll likely need replacing if it's faulty.
Condenser fan: The condenser fan is designed to cool the condenser and condenser coil within the Avanti wine cooler. If it doesn't function, the condenser and coil can overheat - causing the internal area of the wine fridge to heat up too. Take a look at the rear of the unit and make sure the condenser fan is spinning freely and not blocked (by dust / dirt) or making excessive noise due debris or a blockage.
Thermostat: If the Avanti wine fridge thermostat is working correctly, it's responsible for making the condenser, evaporator, fan, and compressor work - so it's super important! The thermostat also allows you to control and adjust the temperature of the wine cooler so if the reading on thermostat is inaccurate (or flat out wrong) the wine cooler temperature will likely be inaccurate too.

Why Is My Avanti Wine Fridge Not Cooling (And How To Fix It) - Expert Wine Storage

Is the motor fan working may be getting too hot. Or you may be able to unplug it for a few minutes then plug it back in.

I've added a link for an Avanti ewcb,
http://www.retrevo.com/support/Avanti-EWC16B-Refrigerators-manual/id/867bh235/t/2/. There you can find a complete manual on the product which will help you to locate where the problem is coming from. hope I've helped!

try leaving unplugged for a couple hours then plug back in

same problem, can not fix. Had a authorized service tech who said that you can not add freon to this unit, the only option is to plant flowers in it.

Order a new control board if it is working after you unplug it it's because the control board is being reset. You can contact the manufacturer and purchase a control board directly from them .

I have the same E4 problem. You can order the PCB from Avanti at Miami Florida or your regional Avanti service rep.

thanks for the question i think the problem is that its under the counter no air flow to cool the coils try it not under counter thanks the appliance doc

pull it out and lay hands on the compressor and see if its running if not replace the thermostat

contact avanti cust svc they are easy to work with and want you happy tell them your promb but i suspect you need a new themostat