Performed Call diagnostics on upstairs mini split and downstairs Mini split. Downstairs is functioning properly at this time. Upstairs has sustained refrigerant loss. Performed electronic leak inspection and found that the upstairs indoor head unit is leaking refrigerant. Unable to determine if it is a flare nut fitting. Need to return with second technician to extract head unit to verify if flare nut connection or welding connection and to recharge system. - thoroughly explained to homeowner that there is a leak on the head unit of this mini split. - homeowner declined repair charges and opted to just top off equipment - homeowner said he was going to have company that installed it come back and make the repairs. - added 2lbs of r410a refrigerant to adjust charge back to manufacturer operating specifications.