I am working on a whirlpool fridge. Compressor not running and the tech sheet is missing. I replace the inverter box but compressor still not running. I and getting 123 volts AC input and 3.3 volts DC to the inverter. I think I need 4-6 volts which leads me to believe that the Main control board may be bad. Inverter is not attempting to start the compressor. Compressor reads 6.4 volts across all leads. Baffled