问题出在低压(24V)电路。cooling is not controled by the board. it iis by t

因此换board 不解决问题很正常。here is what you need to do:
1)check if you have 24v between R and C. Voltage=0,?bad transformer; v=24, go to next
2)at the board, put a jump wire between R and Y (connect R & Y), condenser should be on since you have a new contactor. If not, bad wire between board and contactor.
3)jump R and G, blower should be on.
4)If 2) and 3) both are working, the problem is your thermostat or wire between the board and thermostat.