I found the outdoor unit tripped on a hard lock out. The defrost board did not give any information beyond that. I hooked up my gauges and reset the defrost board. The compressor started with no issues pulling 8.5 amps on start up. I watched the refrigerant pressures and it appears the pressures are low. I covered the unit to simulate a harder day and the subcool was at a 3.1 at the highest and the super heat was 23.3. I offered pricing to add refrigerant and the customer declined. I spoke with the homeowner about part availability and the possibility of finding 410a replacement parts. The system could need more than 3 pounds and this would be determined when adding.