Check status menu to see if the unit is calling the for compressor. (On main board go down or up until you are on “Status Menu” > Enter> Push up all the way up to “Cooling Stages” > Enter > If Y1 has a number).
If Y1 is calling, go to your terminal strip and check the 24V Wire (On the terminal strip, place your Voltmeter on “common” & “Y1”. It should read 24VAC ).
Check pressures to see if the low-pressure switch is off. (Need to charge system with refrigerant).
Check to see if the outdoor fan is on, it may have turned off by high pressure.