System found on hard lock out. Tech did not have access to the airhandler. Dual run capacitor and amp draws checked out good. Found normal refrigerant pressures, superheat and subcool are where they need to be based on manufacturer specs. From the condenser, the liquid line goes from 3/8 to 1/4 in as it goes in between the wall. Previous tech recommended replacing the liquid line due to extreme corrosion. Liquid line is extremely brittle due to corrosion. Tech did increase the subcooling from 10 to 13 due to the elevation, line set length and liquid line size. 20 degrees of delta T was recorded. System is back cooling. Pictures on file. Tech spoke with mark about the findings. Tech operated the system for 20+ minutes and operated without going into lock out or faults. Install warranty.