Arrived on site to diagnose a no cooling on downstairs system. Upon arrival Spoke over with client. They stated son hit thermostat and ripped off the wall and system no longer worked. Thermostat stated low batteries so replaced batteries that client supplied. Thermostat still not operational. Test wires and jumped system on the thermostat side and system was operational. Jumped system from furnace, system was operational. Advised client thermostat is the issue. Cycled system to ensure system is now operational and cooling. Went over repairs and replacement options. Client just wanted to get system up and cooling for the time being. Client did want to go forward with replacing thermostat with a Honeywell T4 Pro only. Installed and cycled system to ensure system is operating after install. Client is aware of the age, condition, and how his system is operating. System is operational and cooling upon departure.