Work Performed: Return visit to diagnose ongoing issue with Daikin mini-split heat pump Previous visit addressed E5 error code, indicating compressor overload (possible overcurrent or overheating) Followed full troubleshooting procedure as outlined by Daikin Tech Hub: Verified voltage supply Tested thermistors Checked compressor winding resistance and insulation to ground All initial diagnostic readings were within acceptable range; Tech Hub advised replacing the inverter (PCB) board Replaced the inverter (PCB) board as instructed, but E5 error code persisted on return visit today Spent over three hours waiting for Daikin Tech Support call-back Worked with Daikin Tech Support representative Ryan, case #248-8528 Repeated diagnostic steps, including thermistor readings, pressure and temperature checks — all readings confirmed normal Tech Support could not identify a reason for the compressor to trip on overload based on current test results Daikin advised escalating the issue to a field