Received work order to service 2 AC units. Performed the annual maintenance service on both units. Checked the coils for rust, blockage, dirt and leaks. Installed anti microbial tablets. Brushed and flushed the condensate drain lines. Customer complained of not being able to shut off the downstairs unit. Began troubleshooting process. Removed the thermostat, unit would not turn off. Moved to the outside condenser checked the electrical junction box for miscellaneous issues, all is good including the circuit board. Contacted Amana tech support to assist in troubleshooting. I was able to trace the issue to the digital signal control box. I was able to reset the components and the AC unit turned off. Upon double checking and testing the unit for proper operation. The unit turned on but does not shut off. The issues are within the digital signal control box. Electrician is needed. Called the office and spoke with management, I was told Customer has an extended warranty and should not be c