sounds like the unit is overshooting setpoint. those units have a suction solenoid and a suction mod valve. sometimes the SSV sticks and sometimes the SMV sticks in the open spots. try and loosen the SSV its the valve on the right hand side if u are facing the unit. pull off the coil and you should hear a "CLICK" sound. if no click then u have either a stuck valve piston or no voltage to the coil. also check the fuses on the controller. if that checks out ok then its the SMV and u have to check the coil resistance 7.8 ohms. try this first and let us know