Arrived on site to diagnose a 1994 Rheem system. Client has 3 system here but we’re are only looking at 1 system for the bedrooms. Client stated he barely moved in 5 years ago and has yet to use system and once he did try to use system heater was not operational. He stated he was checking to make sure all wires were good and connected properly. But decide to call us out. Inspected electrical compartment and found condenser thermostat wires were not connected to board and hanging in compartment. Jumped system at control board and system did not operate. Found voltage coming to system. Found 24v at board. System is calling for heat but induce is not turning on. Found inducer motors is not getting power motor and found board itself spins not sending command to start heating operation. Advised client of findings and would have to replace control board first to continue my evaluation and ensure no other issues. Inspected system and found igniter white and a over range that’s it’s rat